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EC number: 200-554-5 | CAS number: 63-05-8
- Life Cycle description
- Uses advised against
- Endpoint summary
- Appearance / physical state / colour
- Melting point / freezing point
- Boiling point
- Density
- Particle size distribution (Granulometry)
- Vapour pressure
- Partition coefficient
- Water solubility
- Solubility in organic solvents / fat solubility
- Surface tension
- Flash point
- Auto flammability
- Flammability
- Explosiveness
- Oxidising properties
- Oxidation reduction potential
- Stability in organic solvents and identity of relevant degradation products
- Storage stability and reactivity towards container material
- Stability: thermal, sunlight, metals
- pH
- Dissociation constant
- Viscosity
- Additional physico-chemical information
- Additional physico-chemical properties of nanomaterials
- Nanomaterial agglomeration / aggregation
- Nanomaterial crystalline phase
- Nanomaterial crystallite and grain size
- Nanomaterial aspect ratio / shape
- Nanomaterial specific surface area
- Nanomaterial Zeta potential
- Nanomaterial surface chemistry
- Nanomaterial dustiness
- Nanomaterial porosity
- Nanomaterial pour density
- Nanomaterial photocatalytic activity
- Nanomaterial radical formation potential
- Nanomaterial catalytic activity
- Endpoint summary
- Stability
- Biodegradation
- Bioaccumulation
- Transport and distribution
- Environmental data
- Additional information on environmental fate and behaviour
- Ecotoxicological Summary
- Aquatic toxicity
- Endpoint summary
- Short-term toxicity to fish
- Long-term toxicity to fish
- Short-term toxicity to aquatic invertebrates
- Long-term toxicity to aquatic invertebrates
- Toxicity to aquatic algae and cyanobacteria
- Toxicity to aquatic plants other than algae
- Toxicity to microorganisms
- Endocrine disrupter testing in aquatic vertebrates – in vivo
- Toxicity to other aquatic organisms
- Sediment toxicity
- Terrestrial toxicity
- Biological effects monitoring
- Biotransformation and kinetics
- Additional ecotoxological information
- Toxicological Summary
- Toxicokinetics, metabolism and distribution
- Acute Toxicity
- Irritation / corrosion
- Sensitisation
- Repeated dose toxicity
- Genetic toxicity
- Carcinogenicity
- Toxicity to reproduction
- Specific investigations
- Exposure related observations in humans
- Toxic effects on livestock and pets
- Additional toxicological data
Endpoint summary
Administrative data
Key value for chemical safety assessment
- Toxic effect type:
- dose-dependent
Effects on fertility
Description of key information
Androstendione is an endogenous intermediate in steroid hormone synthesis and as such an endogenous precursor of testosterone and estrone, which can be metabolized to estradiol. Exposure during pregnancy may lead to signs of masculinization in the sex organs of a female child. If taken by nursing women androstendione may reach into the mother's milk and thus impair the development of the infant.
Link to relevant study records
- Endpoint:
- screening for reproductive / developmental toxicity
- Type of information:
- experimental study
- Adequacy of study:
- key study
- Reliability:
- 2 (reliable with restrictions)
- Rationale for reliability incl. deficiencies:
- study well documented, meets generally accepted scientific principles, acceptable for assessment
- Principles of method if other than guideline:
- - Principle of test: Thirty-day old rats received corn oil alone or androstenedione (in corn oil) at one of four concentrations (0, 1.0, 5.0, 10.0 or 30.0 mg/kg body weight) by gavage for two weeks prior to mating, during the mating period and throughout gestation
- Parameters analysed / observed: Feed and fluid consumption, Body weight, estrous cycle, number of corpora lutea, the number of implantation sites, and the number and position of resorption sites and fetuses (dead or alive), gravid uterus weight;
fetuses: sex, weight, crown-rump length, anogenital distance, external, skelatal, visceral abnormalities - GLP compliance:
- not specified
- Specific details on test material used for the study:
- SOURCE OF TEST MATERIAL
- Source: Steraloids, Newport, RI
- Purity: >99% - Species:
- rat
- Strain:
- other: CD-CRL: CD-BR
- Sex:
- female
- Details on test animals or test system and environmental conditions:
- TEST ANIMALS
- Source: Charles River Laboratories, Inc. (Wilmington, MA)
- Females nulliparous and non-pregnant: yes
- female (n=60; 49 days old; 150–175 g), male (n=30; 56 days old; 175–200 g)
- Housing:
acclimation period: singly
mating period: two female rats co-habitated with a single male
- Diet (e.g. ad libitum): Purina Rodent Chow 5002 (Purina Mills, Inc., Richmond,
IN), ad libitum
- Water (e.g. ad libitum): ad libitum
- Acclimation period: approx. 1 wk
ENVIRONMENTAL CONDITIONS
- Temperature (°C): 64–79 F
- Humidity (%): 40-70%
- Photoperiod (hrs dark / hrs light): 12/12 - Route of administration:
- oral: gavage
- Vehicle:
- corn oil
- Details on exposure:
- PREPARATION OF DOSING SOLUTIONS:
Dosing solutions were stable for >35 days as determined by HPLC analysis. All solutions of androstenedione were prepared and used according to the results of the stability tests. The dosing solutions were not utilized until HPLC analysis confirmed the solutions were within the prescribed concentrations (±10%). - Details on mating procedure:
- - M/F ratio per cage: 1:2
- Length of cohabitation: 5 times per week for 3 weeks or until mating occurred
- Proof of pregnancy: sperm in vaginal smear referred to as day 0 of pregnancy
The females that did not mate at the end of the week were re-mated with a different
randomly selected male. At the end of the three week mating period, females that did not mate were necropsied. - Analytical verification of doses or concentrations:
- yes
- Duration of treatment / exposure:
- females: 2 weeks prior to mating, during the mating period (up to 3 weeks) and days 0–20 of gestation
male rats were not treated and were only used as sires - Frequency of treatment:
- daily
- Dose / conc.:
- 1 mg/kg bw/day (actual dose received)
- Dose / conc.:
- 5 mg/kg bw/day (actual dose received)
- Dose / conc.:
- 10 mg/kg bw/day (actual dose received)
- Dose / conc.:
- 30 mg/kg bw/day (actual dose received)
- No. of animals per sex per dose:
- 12 females
- Control animals:
- yes, concurrent vehicle
- Parental animals: Observations and examinations:
- serum estradiol, estrone, testosterone and androstenedione levels
- Oestrous cyclicity (parental animals):
- monitored during the 14-day pre-mating dosing period
- Postmortem examinations (parental animals):
- number of corpora lutea, number of implantation sites, number and position of resorption sites and fetuses (dead or alive), gravid uterus weight
- Postmortem examinations (offspring):
- uterine position, sex, weight, crown-rump length, and anogenital distance,
abnormalities (external, skeletal, soft-tissue) - Statistics:
- For the parameters feed and fluid consumption, number of corpora lutea, implants, alive, males and females alive and estrous cyclicity data an Analysis of
Variance (ANOVA) followed by a protected least significance difference (LSD) test (one-tail, if ANOVA p<0.05) was used to compare the control with each
of the treated groups. For the parameters implant efficiency and percent early, late, and total (early+late) resorptions, the data were transformed using a Freeman-Tukey Arc-Sine Transformation followed by an ANOVA and a protected LSD test as discussed above.
An Analysis of Covariance (ANCOVA) followed by a protected LSD (two-tail, if the ANCOVA p<0.05) test was used to compare the control with each treated group for the parameters adult organ weights, and mean body weight gain and gravid uterine weight of pregnant females. The ANCOVA adjusted the body weight gain and the gravid weight by the Day 0 dam weight, and the organ weight by the final dam weight.
For both the fetal weight and crown rump measurements a Nested ANOVA followed by a protected LSD test (p<0.05) was used to compare the control and
treated groups.
A Fisher’s Exact Test was used to compare the treated groups with the control for the incidence of specific softtissue, sternebral, and skeletal variations in fetuses, and clinical signs in female rats and Day 20 fetuses. The of the treated groups for the number of litters with 1+, 2+, or 3+ soft-tissue, sternebral, and skeletal variations.
For the average number of fetuses per litter with 1+, 2+ or 3+ soft-tissue, sternebral, and skeletal variations the data were first transformed by a Freeman-Tukey Arc-Sine transformation. The transformed data were then analyzed using an ANOVA followed by a protected LSD test as explained above. A Nested ANOVA followed by a protected LSD test was used to compare the control and treated groups for the average number of ossified vertebrae in fetuses. - Food consumption and compound intake (if feeding study):
- no effects observed
- Water consumption and compound intake (if drinking water study):
- no effects observed
- Other effects:
- effects observed, treatment-related
- Description (incidence and severity):
- Dose-related increases in serum androstenedione levels were observed in all treated groups, and statistically significant increases were seen in the 5.0, 10.0 and 30.0 mg/kg dose groups. Dose related statistically significant increases in serum estrone levels were observed in all treated groups in comparison to the controls. A dose-related increase in serum estradiol levels was observed in all treated groups, and the increase was significant in the 10.0 and 30.0 mg/kg dose groups.
Serum testosterone levels were elevated in the 10 and 30 mg groups and significantly elevated in the 30.0 mg/kg dose group - Reproductive function: oestrous cycle:
- effects observed, treatment-related
- Description (incidence and severity):
- A statistically significant decrease in the number of androstenedione treated animals having a regular estrous cycle was observed in the 10.0 and 30.0 mg/kg dose groups during the pre-mating period (Table 3). Only one animal from the 10.0 mg/kg dose group had a highly irregular cycle and at least one animal from each androstenedione dose group was acyclic.
- Dose descriptor:
- NOAEL
- Effect level:
- 5 mg/kg bw/day (actual dose received)
- Sex:
- female
- Basis for effect level:
- reproductive function (oestrous cycle)
- Remarks on result:
- other: only females treated
- Mortality / viability:
- mortality observed, treatment-related
- Description (incidence and severity):
- A slight (non-statistically significant) reduction in the mean number of viable fetuses and the mean number of viable male fetuses was observed in the 30.0 mg/kg dose group (Table 4).
- Body weight and weight changes:
- no effects observed
- Description (incidence and severity):
- Androstenedione exposure did not affect sternebral ossification, the incidence of fetal sternebal variations or the incidence of specific fetal skeletal variations.
A statistically significant increase in the number of fetuses with a moderately enlarged ureter at the kidney was observed in the 1.0 and 5.0 mg/kg dose groups, and slight non-statistically significant increases were observed in the 10.0 and 30.0 mg/kg dose groups (Table 5). The average number of soft-tissue variations per litter was similar in both control animals and the androstenedione treated animals (Table 5). Statistically significant differences in dam organ weights expressed per gram of body weight and dam organ weights expressed per gram of brain weight were not observed when values obtained for treated and control groups were compared. - Dose descriptor:
- NOAEL
- Generation:
- F1
- Effect level:
- 10 mg/kg bw/day (actual dose received)
- Sex:
- male/female
- Basis for effect level:
- viability
- Reproductive effects observed:
- yes
- Lowest effective dose / conc.:
- 5 mg/kg bw/day (actual dose received)
- Treatment related:
- yes
- Relation to other toxic effects:
- reproductive effects in the absence of other toxic effects
- Dose response relationship:
- yes
- Relevant for humans:
- yes
- Executive summary:
This study was conducted to characterize the effect of androstenedione on estrous cyclicity, mating behavior and fetal development.
Thirty-day old rats received corn oil alone or androstenedione (in corn oil) at one of four concentrations (0, 1.0, 5.0, 10.0 or 30.0 mg/kg body weight) by gavage for two weeks prior to mating, during the mating period and throughout gestation. Dose related increases in serum androstenedione, estradiol and estrone were observed in all androstenedione treated animals at gestation day 20. A statistically significant increase in serum testosterone concentration was observed in the 30 mg/kg dose group. Feed and fluid consumption were not affected by androstenedione treatment during the pre-mating or gestational periods, however a statistically significant decrease in the number of females with regular estrous cycles was observed in the 10.0 and 30.0 mg/kg dose groups. Exposure to androstenedione did not affect mean body weight gain during pre-mating or gestation. Slight not statistically significant reductions in the number of implants, number of viable fetuses and number of viable male fetuses were observed in the
30.0 mg/kg androstenedione group. Reductions were not observed in the number of corpora lutea. Fetal growth in terms of fetal weight, crown-rump length, anogenital distance and the number of external abnormalities was not affected by androstenedione exposure. At the doses given, androstenedione had no specific effect on the development of individual bones, including sternebrae.
Dose related effects of androstenedione were not observed on the development of soft tissues. A statistically significant increase in moderately enlarged ureter at the kidney was observed in both the 1.0 and 5.0 mg/kg dose groups. Organ weights (expressed per gram of body weight or per gram of brain weight) were not affected by androstenedione treatment.- Endpoint:
- screening for reproductive / developmental toxicity
- Type of information:
- experimental study
- Adequacy of study:
- key study
- Reliability:
- 2 (reliable with restrictions)
- Rationale for reliability incl. deficiencies:
- study well documented, meets generally accepted scientific principles, acceptable for assessment
- Principles of method if other than guideline:
- - Principle of test: Thirty-day old rats received corn oil alone or androstenedione (in corn oil) at one of four concentrations (5.0, 10.0, 30.0 or 60.0 mg/kg body weight) by gavage for two weeks prior to mating, during the mating period and throughout gestation. Caesarean sections were performed on GD 20.
- Parameters analysed / observed: serum androstenedione, estradiol, testosterone, progesterone, LH and FSH, feed and fluid consumption, Body weight, estrous cycle, number of corpora lutea, the number of implantation sites, and the number and position of resorption sites and fetuses (dead or alive), gravid uterus weight;
fetuses: sex, weight, crown-rump length, anogenital distance, external, skelatal, visceral abnormalities - GLP compliance:
- yes
- Specific details on test material used for the study:
- SOURCE OF TEST MATERIAL
- Source: Steraloids, Newport, RI
- Purity: >99% - Species:
- rat
- Strain:
- other: CD-CRL:CD-BR, VAF+
- Sex:
- female
- Details on test animals or test system and environmental conditions:
- TEST ANIMALS
- Source: Charles River Laboratories, Inc. (Wilmington, MA)
- Females nulliparous and non-pregnant: yes
- female (49 days old; 150–175 g), male (56 days old; 175–200 g)
- Housing:
acclimation period: singly
mating period: two female rats co-habitated with a single male
- Diet (e.g. ad libitum): Purina Rodent Chow 5002M (Purina Mills, Inc., Richmond,
IN), ad libitum
- Water (e.g. ad libitum): ad libitum
- Acclimation period: approx. 1 wk
ENVIRONMENTAL CONDITIONS
- Temperature (°C): 64–79 F
- Humidity (%): 40-70%
- Photoperiod (hrs dark / hrs light): 12/12 - Route of administration:
- oral: gavage
- Vehicle:
- corn oil
- Details on exposure:
- PREPARATION OF DOSING SOLUTIONS:
Dosing solutions were stable for >35 days as determined by HPLC analysis. All solutions of androstenedione were prepared and used according to the results of the stability tests. The dosing solutions were only utilized after HPLC analysis confirmed that the solutions were within the prescribed concentrations (±10%). - Details on mating procedure:
- - M/F ratio per cage: 1:2
- Length of cohabitation: approximately 15 h/day, 5 days/week for up to 3 weeks or until mating occurred
- Proof of pregnancy: sperm in vaginal smear referred to as day 0 of pregnancy
The females that did not mate at the end of the week were re-mated with a different
randomly selected male. At the end of the three-week mating period, females that did not mate (n = 3) were necropsied. - Analytical verification of doses or concentrations:
- yes
- Duration of treatment / exposure:
- Female rats received androstenedione in corn oil via intragastric intubations for
two weeks prior to mating, during the mating period and during GD 0–19.
The male rats were not treated and were only used as sires therefore the effect of androstenedione on male reproductive function was not tested in this study. - Frequency of treatment:
- daily
- Dose / conc.:
- 5 mg/kg bw/day (actual dose received)
- Dose / conc.:
- 10 mg/kg bw/day (actual dose received)
- Dose / conc.:
- 30 mg/kg bw/day (actual dose received)
- Dose / conc.:
- 60 mg/kg bw/day (actual dose received)
- No. of animals per sex per dose:
- The distribution of the animals among 0 control, 00 control, 5, 10, 30 and 60 mg/kg dose groups were 39, 29, 39, 29, 33 and 40, respectively.
(The control group (double dose control or ‘‘00’’ control) for the animals receiving androstenedione at a concentration of 60 mg/kg body weight received 0.6 ml corn oil alone per 100 g body weight.) - Control animals:
- yes, concurrent vehicle
- Details on study design:
- Experimental animals received androstenedione in corn oil at 5.0, 10.0, 30.0 or 60 mg/kg of body weight. The dosages utilized in the present study were derived based on an androstenedione exposure of approximately 400 mg androstenedione taken per day (100 mg taken 4 times/day) by an individual weighing approximately 70 kg. The animals utilized in the present study were exposed to androstenedione at approximately 1, 2, 6 or 10 times this dose.
- Oestrous cyclicity (parental animals):
- The estrous cycles of randomly selected female rats (n = 20 rats/group) from the single and double dose control groups as well as the 30 and 60 mg/kg androstenedione treatment groups were monitored daily during the two week
pre-mating exposure period. - Postmortem examinations (parental animals):
- number of corpora lutea, the number of implantation sites, and the number and position of resorption sites and fetuses (dead or alive), gravid uterus weight
- Postmortem examinations (offspring):
- Each viable fetus was removed from the uterus and examined individually
for any gross external morphological effects.
Records were kept as to its uterine position, sex, weight, crown-rump length, and anogenital distance, as well as any externally visible abnormalities.
A subset of fetuuses were examined for skeletal anomalies or soft-tissue anomalies. - Statistics:
- A p value of =0.05 was considered statistically significant. For the parameters feed and fluid consumption, number of corpora lutea, implants, alive, males and females alive and estrous cyclicity data, an Analysis of Variance (ANOVA) followed by a protected least significance difference (LSD) test (one-tail, if ANOVA p < 0.05) was used to compare the two control groups as well as each control group with their respective treatment group(s). For the parameters implantation efficiency and percent early, late, and total (early + late) resorptions, the data were transformed using a Freeman–Tukey Arc–Sine Transformation followed by an ANOVA and a protected LSD test as discussed above.
An Analysis of Covariance (ANCOVA) followed by a protected LSD (two-tail, if the ANCOVA p < 0.05) test was used to compare the control with each treated group for the parameters adult organ weights, and mean body weight gain and gravid uterine weight of pregnant females. The ANCOVA adjusted the body weight gain
and the gravid weight by day 0 dam weight, and the organ weight by the final dam weight. For both the fetal weight and crown rump measurements, a Nested ANOVA followed by a protected LSD test (p < 0.05) was used to compare the control and treated groups. A Fisher's Exact Test was used to compare the treated groups with the control for the incidence of specific soft-tissue variations in fetuses, and clinical external signs in female rats and day 20 fetuses. - Body weight and weight changes:
- no effects observed
- Food consumption and compound intake (if feeding study):
- no effects observed
- Water consumption and compound intake (if drinking water study):
- no effects observed
- Organ weight findings including organ / body weight ratios:
- effects observed, treatment-related
- Reproductive function: oestrous cycle:
- effects observed, treatment-related
- Description (incidence and severity):
- The mean number of estrous cycles observed during the 14 day pre-treatment in the 60 mg/kg androstenedione treatment group (2.85 ± 0.15) was significantly different from the double dose control group (3.45 ± 0.15). (Table 2) Similar effects were not observed when the single dose control group was compared with the 30 mg/kg dose group.
- Reproductive performance:
- no effects observed
- Description (incidence and severity):
- The time to mating was not affected as most animals mated within the first
week of co-habitation. Effects were not observed in the numbers of pregnant females, corpora lutea, implants, implantation efficiency, early and late deaths. - Dose descriptor:
- NOAEL
- Effect level:
- 30 mg/kg bw/day (actual dose received)
- Sex:
- female
- Basis for effect level:
- reproductive function (oestrous cycle)
- Dose descriptor:
- NOAEL
- Generation:
- F1
- Effect level:
- 60 mg/kg bw/day (actual dose received)
- Sex:
- male/female
- Basis for effect level:
- other:
- Remarks on result:
- other: At the doses given, androstenedione had no specific effect on the development of individual bones or soft tissues.
- Reproductive effects observed:
- yes
- Lowest effective dose / conc.:
- 60 mg/kg bw/day (actual dose received)
- Treatment related:
- yes
- Relation to other toxic effects:
- reproductive effects in the absence of other toxic effects
- Dose response relationship:
- not specified
- Relevant for humans:
- yes
- Executive summary:
Thirty-day old female rats received corn oil or androstenedione (in corn oil) at one of four concentrations (5.0, 10.0, 30.0 or 60.0 mg/kg body weight) by gavage for two weeks prior to mating, during the mating period and until gestation day (GD) 19. Caesarean sections were performed on GD 20. No dose related changes were observed in serum androstenedione, estradiol, LH, FSH, testosterone or progesterone. A statistically significant decrease in estrous cycle length was observed in the 60.0 mg/kg dose group only. Feed and fluid consumption, mean body weight gain, organ weight and fetal parameters were not affected by androstenedione treatment. At the doses given, androstenedione had no specific effect on the development of individual bones or soft tissues.
Referenceopen allclose all
Table 1: Mean serum endocrine parameters (±SEM) from day 20 pregnant rats
Dose (mg/kg) | 0 | 1.0 | 5.0 | 10.0 | 30.0 |
No. Dams | 11 | 11 | 10 | 11 | 10 |
Androstenedione (ng/ml) | 1.27±0.15 | 1.36±0.14 | 1.83±0.20** | 2.19±0.25** | 4.71±0.41**** |
Estradiol (pg/ml) | 65.86±4.94 | 77.54±7.72 | 79.89±7.12 | 90.63±6.43* | 128.34±10.86**** |
Estrone (pg/ml) | 33.02±4.92 | 42.37±3.72* | 55.97±6.24** | 62.26±7.05**** | 110.79±13.82**** |
Testosterone (ng/ml | 0.21±0.03 | 0.18±0.04 | 0.19±0.03 | 0.27±0.03 | 0.70±0.11**** |
Asterisks indicate significant difference from controls (* p</=0.05; ** p</=0.01; *** p</=0.001; **** p</=0.0001).
Table 2: Mean feed and fluid consumption and body weight during the pre-mating period
Days | Dose (mg/kg) |
|
|
|
|
0 | 1.0 | 5.0 | 10.0 | 30.0 | |
Feed Consumption (g±SEM) | |||||
0–14a | 209.9±3.9 | 205.2±4.3 | 201.6±4.1 | 214.2±6.0 | 219.2±5.4 |
0–20b
| 401.3±7.1 | 399.6±14.0 | 400.0±7.4 | 408.3±8.7 | 400.9±11.4 |
Fluid Consumption (ml±SEM) | |||||
0–14a
| 376.4±18.1 | 388.3±26.5 | 369.2±17.6 | 415.8±23.7 | 404.7±15.1 |
0–20b
| 642.5±25.9 | 684.3±34.7 | 644.4±24.0 | 727.7±30.4 | 656.2±19.1 |
Terminal Body Weight (g±SEM) | |||||
14a
| 225.4±3.7 | 223.2±3.5 | 222.7±3.1 | 230.6±5.1 | 236.6±4.5 |
20b
| 364.1±5.3 | 361.5±9.9 | 365.4±6.1 | 368.5±9.7 | 366.3±8.2 |
Mean Body Weight Gain (g±SEM) | |||||
0–14a | 37.4±3.5 | 32.7±2.6 | 33.4±3.5 | 40.6±2.8 | 45.8±3.0 |
0–20b | 136.2±2.0 | 139.3±7.2 | 138.8±4.7 | 134.2±6.8 | 125.7±6.2 |
Adjusted Weight Gain (g±SEM) | |||||
20b,c | 56.4±3.3 | 58.2±4.0 | 59.7±4.0 | 57.8±3.5 | 57.1±7.2 |
a n=12 animals per group.
b n=11, 11, 10, 11, 10 animals per group for the 0.0, 1.0, 5.0, 10.0 and 30.0 mg/kg body weight dose groups.
c Total weight gain minus gravid uterine weight.
Table 3: Summary of estrous cycle measurements collected for 14 consecutive days prior to mating for female rats treated with androstenedione
Dose Level (mg/kg) | 0 | 1.0 | 5.0 | 10.0 | 30.0 |
No. Dams | 12 | 12 | 12 | 12 | 12 |
Regular Cycle (4-5 Days) | 10 | 8 | 9 | 5* | 5* |
Irregular Cycle (3, 6–10 Days) | 2 | 3 | 2 | 5 | 5 |
Highly Irregular Cycle (11–13 Days) | 0 | 0 | 0 | 1 | 0 |
Acyclic (14 Days) | 0 | 1 | 1 | 1 | 2 |
Total No. Estrous Cycles | 42 | 34 | 34 | 31 | 28 |
Mean No. Estrous Cycles (Mean±SEM) | 3.6±0.2
| 2.9±0.2*
| 2.9±0.2*
| 2.9±0.1**
| 2.4±0.2** |
Asterisks indicate significant difference from controls (* p</=0.05; ** p</=0.01).
Table 4: Analysis of maternal and reproductive autopsy findings
Dose Level (mg/kg) | 0 | 1.0 | 5.0 | 10.0 | 30.0 |
No of pregnant females | 11 | 11 | 10 | 11 | 10 |
Corpora Lutea (Mean±SEM) | 14.45±0.41 | 14.91±0.44 | 15.40±0.72 | 14.91±0.49 | 14.60±0.54 |
Implants (Mean±SEM) | 14.00±0.50 | 13.82±1.02 | 14.20±0.76 | 13.45±1.11 | 12.70±1.03 |
Implantation Efficiency | 96.84±2.00 | 92.18±5.74 | 93.11±4.36 | 90.08±6.97 | 86.94±6.43 |
Av. Percent early / late deaths/litter (%, Mean±SEM) | 4.43±1.73 | 2.92±1.57 | 5.17±2.25 | 3.60±1.37 | 7.90±3.03 |
Viable Fetuses (Mean±SEM) | 13.36±0.51 | 13.36±0.97 | 13.50±0.86 | 12.91±1.05 | 11.60±0.97 |
Male | 6.45±0.37 | 6.36±0.72 | 6.30±0.73 | 6.36±0.59 | 4.50±0.52 |
Female | 6.91±0.65 | 7.00±0.74 | 7.20±0.55 | 6.55±0.68 | 7.10±0.62 |
Sex Distribution (%) | |||||
Male | 48.30 | 47.62 | 46.67 | 49.30 | 38.79 |
Female | 51.70 | 52.38 | 53.33 | 50.70 | 61.21 |
Fetal body weight (g, Mean±SEM) | |||||
Males | 3.99±0.03 | 4.06±0.04 | 3.87±0.04 | 3.91±0.05 | 3.92±0.06 |
Females | 3.81±0.03 | 3.83±0.03 | 3.71±0.03 | 3.73±0.04 | 3.63±0.06 |
Fetal crown-rump length (cm, Mean±SEM) | |||||
Males | 4.1±0.01 | 4.2±0.02 | 4.1±0.01 | 4.1±0.02 | 4.1±0.02 |
Females | 4.0±0.01 | 4.0±0.01 | 4.0±0.01 | 4.0±0.01 | 4.0±0.02 |
No. runts (litters with runts) | |||||
Males) | 0(0) | 0(0) | 0(0) | 2(1) | 1(1) |
Females | 0(0) | 0(0) | 0(0) | 1(1) | 2(2) |
Table 5: Incidence of specific fetal soft-tissue variations
Dose Level (mg/kg) | 0 | 1.0 | 5.0 | 10.0 | 30.0 |
No. fetuses (litters) examined | 76(11) | 73(11) | 69(10) | 70(11) | 57(10) |
Hemorrhage, internal | 1(1) | 1(1) | - | - | - |
Hydroureter, severe | 1(1) | 8(4) | 4(4) | 2(2) | 4(3) |
Hydroureter, moderate | 5(4) | 13(6) | 15(8) | 8(5) | 11(7) |
Enlarged renal pelvis, severe | - | - | - | - | - |
Enlarged renal pelvis, moderate | 1(1) | - | 1(1) | - | 1(1) |
Enlarged ureter at kidney, severe | 2(2) | 7(4) | 3(2) | 3(2) | 5(3) |
Enlarged ureter at kidney, moderate | 5(2) | 15(7)* | 17(9)** | 9(6) | 7(6) |
Kidney, ectopic | 3(3) | - | - | - | - |
Cleft Palate | 1(1) | - | - | - | - |
Undescended Testicle | - | - | - | - | 1(1) |
Number of litters involved in parentheses. Asterisks indicate: * p</=0.05; ** p</=0.01
The average number of soft-tissue variations per litter was similar in both control animals and the androstenedione treated animals except for a statistically significant increase in the number of fetuses with a moderately enlarged renal pelvis in the 30 mg/kg dose group (Table 5).
The increase appears to be random because of a lack of effect at 60 mg/kg. Exposure to androstenedione at the doses utilized in the present study did not affect fetal ossification.
Table 1: Serum endocrine parameters (mean ± SEM) from day 20 pregnant rats (a)
| Dose levels (mg/kg) | |||||
| 0 (19) | 00 (21) | 5.0 (25) | 10.0 (27) | 30.0 (24) | 60.0 (27) |
Androstenedione b | 1.67 ± 0.14 | 1.65 ± 0.16 | 1.53 ± 0.10 | 1.64 ± 0.11 | 1.75 ± 0.10 | 1.67 ± 0.11 |
Estradiol c | 61.68 ± 3.51 | 50.60 ± 3.96 | 56.09 ± 4.30 | 54.29 ± 3.59 | 62.61 ± 4.51 | 57.08 ± 3.24 |
LH d,b | 1.06 ± 0.07 | 1.12 ± 0.04 | 1.28 ± 0.10 | 1.30 ± 0.15 | 1.08 ± 0.06 | 1.07 ± 0.07 |
FSH b | 5.92 ± 0.38 | 6.13 ± 0.31 | 6.53 ± 0.32 | 6.26 ± 0.27 | 6.53 ± 0.37 | 5.81 ± 0.26 |
Testosterone b | 0.47 ± 0.06 | 0.59 ± 0.08 | 0.48 ± 0.06 | 0.48 ± 0.04 | 0.52 ± 0.06 | 0.46 ± 0.05 |
Progesterone b | 16.68 ± 1.99 | 16.15 ± 2.50 | 15.57 ± 1.78 | 15.53 ± 1.80 | 17.04 ± 1.79 | 16.82 ± 1.34 |
( ) = number of litters.
a If the p value is not given then p > 0.10.
b Data expressed in ng/ml.
c Data expressed in pg/ml.
d Data transformed using a log transformation.
Table 2: Estrous cycle measurements during 14-day pre-mating period (day, mean ± SEM)
| Dose levels (mg/kg) | |||
| 0 (20) | 00 (20) | 30.0 (20) | 60.0 (20) |
Regular cycle (4–5 days) | 2.05 ± 0.17 | 2.20 ± 0.17 | 2.05 ± 0.17 | 1.65 ± 0.18 |
Irregular cycle (2,3,6–10 days) | 0.25 ± 0.12 | 0.25 ± 0.14 | 0.10 ± 0.07 | 0.30 ± 0.15 |
Highly irregular cycle (11–13 days) | 0.00 ± 0.00 | 0.00 ± 0.00 | 0.05 ± 0.05 | 0.00 ± 0.00 |
Acyclic (14 days) | 0.00 ± 0.00 | 0.00 ± 0.00 | 0.00 ± 0.00 | 0.00 ± 0.00 |
Number of estrous stages observed | 3.30 ± 0.13 | 3.45 ± 0.15 | 3.20 ± 0.14 | 2.85 ± 0.15* |
( ) = number of animals per group.
*Indicates statistically significant difference from the ‘‘00’’ control group; p </= 0.05.
Table 3: Mean feed and fluid consumption and body weight gain during pre-mating (days 0–14) and gestation (days 0–20) a
| Dose levels (mg/kg) | |||||
| 0 | 00 | 5.0 | 10.0 | 30.0 | 60.0 |
Feed consumption (g ± SEM) | ||||||
0–14 b | 229.3 ± 2.7 | 207.4 ± 2.3 | 231.7 ± 3.0 | 225.0 ± 2.9 | 229.2 ± 2.7 | 211.9 ± 1.7 |
0–20 c | 399.2 ± 6.0 | 344.7 ± 6.2 | 396.9 ± 6.2 | 397.3 ± 7.0 | 402.6 ± 5.8 | 358.6 ± 4.3 |
Fluid consumption (ml ± SEM) | ||||||
0–14 b | 387.8 ± 9.7 | 376.0 ± 10.6 | 375.0 ± 10.1 | 356.5 ± 10.9 | 390.8 ± 8.1 | 363.7 ± 7.0 |
0–20 c | 727.7 ± 16.8 | 650.9 ± 24.0 | 698.5 ± 17.4 | 711.3 ± 24.6 | 732.3 ± 18.8 | 655.3 ± 14.2 |
Mean body weight gain (g ± SEM) | ||||||
0–14 b, d | 34.4 ± 1.7 | 31.8 ± 1.4 | 34.1 ± 1.5 | 34.5 ± 1.7 | 37.5 ± 1.6 | 38.6 ± 1.3 |
0–20 c, d | 138.4 ± 4.6 | 132.0 ± 7.1 | 133.6 ± 4.3 | 134.5 ± 4.7 | 134.2 ± 5.2 | 131.9 ± 4.7 |
a If p value not given p > 0.10.
b n = 47, 38, 39, 30, 41 and 57 animals for the 0, 00, 5.0, 10.0, 30.0 and 60 mg/kg dose groups, respectively.
c n = 39, 29, 39, 29, 33 and 40 animals for the 0, 00, 5.0, 10.0, 30.0 and 60 mg/kg dose groups, respectively.
d Total weight gain minus gravid uterine weight.
Table 4: Analysis of maternal and reproductive necropsy findings (a)
Dose level (mg/kg) | ||||||
0 (39) | 00 (29) | 5.0 (39) | 10.0 (29) | 30.0 (33) | 60.0 (40) | |
No. (%) of pregnant females | ||||||
37 (95) | 27 (93) | 38 (97) | 28 (97) | 32 (97) | 38 (95) | |
Corpora lutea (Mean ± SEM) | ||||||
16.27 ± 0.29 | 16.19 ± 0.52 | 16.03 ± 0.46 | 16.86 ± 0.39 | 16.03 ± 0.41 | 16.13 ± 0.38 | |
Implants/litter (Mean ± SEM) | ||||||
15.27 ± 0.30 | 14.89 ± 0.70 | 14.03 ± 0.66 | 14.86 ± 0.58 | 14.44 ± 0.52 | 14.21 ± 0.57 | |
Implantation efficiency (%, Mean ± SEM) | ||||||
94.14 ± 1.34 | 90.47 ± 3.45 | 86.88 ± 3.09 | 88.12 ± 2.91 | 89.63 ± 2.56 | 87.63 ± 3.04 | |
Early + late deaths/litter (%, Mean ± SEM) | ||||||
3.96 ± 0.84 | 6.50 ± 3.69 | 2.55 ± 0.69 | 7.14 ± 2.10 | 9.53 ± 3.21 | 4.20 ± 0.89 | |
Viable fetuses/litter (Mean ± SEM) | ||||||
14.68 ± 0.32 | 14.44 ± 0.73 | 13.61 ± 0.62 | 13.79 ± 0.62 | 13.44 ± 0.61 | 13.61 ± 0.56 | |
Total number of fetuses (litters) | ||||||
Male | 276 (37) | 195 (26) | 273 (38) | 176 (28) | 221 (31) | 264 (38) |
Female | 267 (37) | 195 (26) | 244 (38) | 210 (28) | 209 (31) | 253 (37) |
Viable fetuses/litter (Mean ± SEM) | ||||||
Male | 7.46 ± 0.32 | 7.22 ± 0.53 | 7.18 ± 0.43 | 6.29 ± 0.51 | 6.91 ± 0.44 | 4.50 ± 0.52 |
Female | 7.22 ± 0.39 | 6.95 ± 0.39 | 6.42 ± 0.37 | 7.50 ± 0.49 | 6.53 ± 0.42 | 7.10 ± 0.62 |
Anogenital distance (Mean ± SEM) | ||||||
Male | 3.40 ± 0.02 | 3.40 ± 0.03 | 3.40 ± 0.02 | 3.34 ± 0.03 | 3.38 ± 0.02 | 3.45 ± 0.02 |
Female | 1.68 ± 0.01 | 1.73 ± 0.02 | 1.69 ± 0.01 | 1.66 ± 0.02 | 1.74 ± 0.02 | 1.76 ± 0.01 |
Sex distribution (%) | ||||||
Male | 50.83 | 50 | 52.8 | 45.6 | 51.4 | 51.06 |
Female | 49.17 | 50 | 47.2 | 44 | 48.6 | 48.94 |
Fetal body weight (g, Mean ± SEM) | ||||||
Males | 3.80 ± 0.02 | 3.70 ± 0.02 | 3.76 ± 0.02 | 3.75 ± 0.03 | 3.74 ± 0.03 | 3.73 ± 0.03 |
Females | 3.63 ± 0.02 | 3.54 ± 0.02 | 3.56 ± 0.02 | 3.56 ± 0.03 | 3.62 ± 0.02 | 3.59 ± 0.02 |
Fetal crown-rump length (cm, Mean ± SEM) | ||||||
Males | 4.02 ± 0.01 | 3.99 ± 0.01 | 4.01 ± 0.01 | 4.01 ± 0.01 | 4.00 ± 0.01 | 3.99 ± 0.01 |
Females | 3.94 ± 0.01 | 3.92 ± 0.01 | 3.91 ± 0.01 | 3.93 ± 0.01 | 3.94 ± 0.01 | 3.91 ± 0.01 |
No. runts (litters with runts) | ||||||
Males | 1 (1) | 2 (2) | 1 (1) | 2 (2) | 2 (2) | 5 (5) |
Females | 3 (3) | 0 (0) | 2 (2) | 2 (2) | 0 (0) | 4 (4) |
a If the p value is not given then p > 0.10.
Table 5: Representative incidence of specific fetal soft-tissue variations *
Dose level (mg/kg) | 0 | 0 | 5 | 10 | 30 | 60 |
No. fetuses (litters) examined | 236 (35) | 196 (26) | 225 (36) | 194 (28) | 214 (31) | 232 (37) |
Hydroureter, severe | 6 (5) | 7 (5) | 5 (5) | 10 (6) | 4 (4) | 10 (7) |
Hydroureter, moderate | 0 (0) | 24 (12) | 0 (0) | 0 (0) | 0 (0) | 13 (11) |
Enlarged renal pelvis, moderate | 6 (3) | 8 (7) | 14 (8) | 8 (5) | 12 (10)* | 12 (9) |
Enlarged ureter at kidney, severe | 12 (7) | 16 (8) | 11 (7) | 10 (6) | 4 (4) | 9 (7) |
Enlarged ureter at kidney, moderate | 16 (12) | 15 (8) | 23 (14) | 20 (12) | 17 (13) | 18 (14) |
Kidney, ectopic | 1 (1) | 0 (0) | 1 (1) | 1 (1) | 1 (1) | 3 (3) |
Anophthalmia | 0 (0) | 0 (0) | 0 (0) | 0 (0) | 0 (0) | 1 (1) |
( ) = number of litters.
*p 6 0.05.
Table 6A: Absolute organ weights for selected maternal organs (g, mean ± SEM)
Dose level (mg/kg) | ||||||
0 (31) | 00 (26) | 5.0 (33) | 10.0 (28) | 30.0 (32) | 60.0 (33) | |
Heart | 0.913 ± 0.016 | 0.882 ± 0.014 | 0.909 ± 0.011 | 0.902 ± 0.015 | 0.892 ± 0.015 | 0.942 ± 0.034 |
Liver | 14.531 ± 0.241 | 14.282 ± 0.238 | 13.987 ± 0.280 | 14.215 ± 0.288 | 14.237 ± 0.276 | 14.647 ± 0.243 |
Spleen | 0.710 ± 0.065 | 0.609 ± 0.016 | 0.621 ± 0.023 | 0.647 ± 0.019 | 0.611 ± 0.014 | 0.604 ± 0.012 |
Adrenal | ||||||
Rt. | 0.035 ± 0.002 | 0.033 ± 0.001 | 0.035 ± 0.001 | 0.032 ± 0.001 | 0.032 ± 0.001 | 0.030 ± 0.001 |
Lft. | 0.037 ± 0.002 | 0.033 ± 0.001 | 0.036 ± 0.001 | 0.033 ± 0.001 | 0.032 ± 0.001 | 0.030 ± 0.001 |
Both | 0.072 ± 0.003 | 0.066 ± 0.002 | 0.071 ± 0.002 | 0.065 ± 0.002 | 0.064 + 0.002 | 0.060 ± 0.002 |
Ovary | ||||||
Rt. | 0.077 ± 0.003 | 0.072 ± 0.002 | 0.074 ± 0.002 | 0.070 ± 0.002 | 0.076 ± 0.003 | 0.074 ± 0.003 |
Lft. | 0.072 + 0.002 | 0.071 ± 0.003 | 0.070 ± 0.0021 | 0.072 ± 0.002 | 0.071 ± 0.002 | 0.070 ± 0.003 |
Both | 0.150 + 0.004 | 0.143 ± 0.003 | 0.144 ± 0.0042 | 0.142 ± 0.003 | 0.147 ± 0.004 | 0.144 ± 0.005 |
Brain | 1.898 ± 0.014 | 1.879 ± 0.021 | 1.888 ± 0018 | 1.925 ± 0.016 | 1.910 ± 0.016 | 1.889 ± 0.016 |
( ) = number of organs examined.
Table 6B: Organ to brain weight ratios for selected maternal organs (g, mean ± SEM)
Dose level (mg/kg) | ||||||
0 (31) | 00 (26) | 5.0 (33) | 10.0 (28) | 30.0 (32) | 60.0 (33) | |
Heart | 0.481 ± 0.008 | 0.470 ± 0.008 | 0.482 ± 0.006 | 0.469 ± 0.008 | 0.468 ± 0.008 | 0.498 ± 0.016 |
Liver | 7.659 ± 0.144 (25)a | 7.625 ± 0.155 | 7.458 ± 0.156 | 7.390 ± 0.150 | 7.463 ± 0.150 (26)a | 7.776 ± 0.133 (27)a |
Spleen | 0.373 ± 0.032 | 0.325 ± 0.008 | 0.392 ± 0.012 | 0.337 ± 0.011 | 0.320 ± 0.006 | 0.320 ± 0.006 |
Adrenal | ||||||
Rt. | 0.018 ± 0.001 | 0.018 ± 0.001 | 0.018 ± 0.001 | 0.017 ± 0.001 | 0.017 ± 0.001 | 0.016 ± 0.001** |
Lft. | 0.019 ± 0.001 | 0.018 ± 0.001 | 0.019 ± 0.001 | 0.017 ± 0.001* | 0.017 ± 0.001* | 0.016 ± 0.001** |
Both | 0.037 ± 0.001 | 0.036 ± 0.001 | 0.037 ± 0.001 | 0.034 ± 0.001* | 0.034 + 0.001* | 0.032 ± 0.001** |
Ovary | ||||||
Rt. | 0.041 ± 0.001 | 0.038 ± 0.001 | 0.039 ± 0.002 | 0.037 ± 0.001 | 0.040 ± 0.002 | 0.039 ± 0.002 |
Lft. | 0.038 + 0.001 | 0.038 ± 0.002 | 0.037 ± 0.001 | 0.037 ± 0.001 | 0.0378 ± 0.001 | 0.037 ± 0.002 |
Both | 0.079 + 0.002 | 0.076 ± 0.002 | 0.076 ± 0.002 | 0.074 ± 0.002 | 0.077 ± 0.002 | 0.076 ± 0.002 |
( ) = number of organs examined.
* Significantly different than the ‘‘0’’ control group, p </= 0.05.
** Significantly different than the ‘‘00’’ control group, p </= 0.05.
a Indicates that six livers were transferred to another protocol.
Effect on fertility: via oral route
- Endpoint conclusion:
- adverse effect observed
Effect on fertility: via inhalation route
- Endpoint conclusion:
- no study available
Effect on fertility: via dermal route
- Endpoint conclusion:
- no study available
Additional information
Androstendione is an endogenous intermediate in steroid hormone synthesis and as such an endogenous precursor of testosterone and estrone, which can be metabolized to estradiol. Exposure during pregnancy may lead to signs of masculinization in the sex organs of a female child. If taken by nursing women androstendione may reach into the mother's milk and thus impair the development of the infant.
For an assessment of steroid hormones see also the argumentation for steroid hormones related to the Technical Rule for Hazardous Substances 905, which was elaborated by the German Committee on Hazardous Substances (AGS) and published by the German Federal Ministry of Labour and Social Affairs (version of 2008/2005/1999, only available in german, (http://www.baua.de/de/Themen-von-A-Z/Gefahrstoffe/TRGS/Begruendungen-905-906.html). In this argumentation 73 steroid hormones or precursors of steroid hormones were each allocated to one of seven hormone classes based on their predominant pharmacological activity (i.e. androgenic, mild androgenic, anabolic, estrogenic, gestagenic, mild gestagenic or glucocorticoide), and recommendations for their classification were elaborated.
For reproductive toxicity classification warranted as Repr. 1A (H360F/D: May damage fertility or the unborn child) according to Regulation (EC) 1272/2008. Additionally, classification is warranted for effects on or via lactation H362 according to Regulation (EC) 1272/2008 (May cause harm to breast-fed children).
A study was conducted to characterize the effect of androstenedione on estrous cyclicity, mating behavior and fetal development.
Thirty-day old rats received corn oil alone or androstenedione (in corn oil) at one of four concentrations (0, 1.0, 5.0, 10.0 or 30.0 mg/kg body weight) by gavage for two weeks prior to mating, during the mating period and throughout gestation. Dose related increases in serum androstenedione, estradiol and estrone were observed in all androstenedione treated animals at gestation day 20. A statistically significant increase in serum testosterone concentration was observed in the 30 mg/kg dose group. Feed and fluid consumption were not affected by androstenedione treatment during the pre-mating or gestational periods, however a statistically significant decrease in the number of females with regular estrous cycles was observed in the 10.0 and 30.0 mg/kg dose groups. Exposure to androstenedione did not affect mean body weight gain during pre-mating or gestation. Slight not statistically significant reductions in the number of implants, number of viable fetuses and number of viable male fetuses were observed in the
30.0 mg/kg androstenedione group. Reductions were not observed in the number of corpora lutea. Fetal growth in terms of fetal weight, crown-rump length, anogenital distance and the number of external abnormalities was not affected by androstenedione exposure. At the doses given, androstenedione had no specific effect on the development of individual bones, including sternebrae.
Dose related effects of androstenedione were not observed on the development of soft tissues. A statistically significant increase in moderately enlarged ureter at the kidney was observed in both the 1.0 and 5.0 mg/kg dose groups. Organ weights (expressed per gram of body weight or per gram of brain weight) were not affected by androstenedione treatment.
In a second study thirty-day old female rats received corn oil or androstenedione (in corn oil) at one of four concentrations (5.0, 10.0, 30.0 or 60.0 mg/kg body weight) by gavage for two weeks prior to mating, during the mating period and until gestation day (GD) 19. Caesarean sections were performed on GD 20. No dose related changes were observed in serum androstenedione, estradiol, LH, FSH, testosterone or progesterone. A statistically significant decrease in estrous cycle length was observed in the 60.0 mg/kg dose group only. Feed and fluid consumption, mean body weight gain, organ weight and fetal parameters were not affected by androstenedione treatment. At the doses given, androstenedione had no specific effect on the development of individual bones or soft tissues.
Further data on reproductive toxicity/fertility are cited in RTECS database (April 2013):
The subcutaneous administrations of androstendione to male rats over 25 days prior to mating result in no further specified effects on spermatogenesis (including genetic material, sperm morphology, motility, and count) testes, epididymis and sperm duct; TDLo: 10500 µg/kg (25D male) [Acta Medica Turcica. (Dr. Ayhan Okcuoglu, Cocuk Hastalikari Klinigi, c/o Ankara Univ., Tip Facultesi, Cebeci, Ankara, Turkey) V.1-10/11, 1948-58: New series: V.1- 1964- v. 8, p. 68, 1971 (AMTUA3)]
The subcutaneous administrations of androstendione to female rats over 14 days prior to mating result in maternal effects on ovaries, fallopian tubes, uterus, cervix and vagina and not further specified effects on fertility; TDLo: 7 mg/kg (14D pre) [Contraception. (Geron-X, Inc., POB 1108, Los Altos, CA 94022) V.1- 1970- v. 5, p. 489, 1972 (CCPTAY)]
The administration of androstendione to female rats via an implantat over16 days prior to mating results in menstrual cycle changes or disorders and not further specified effects on fertility ; TDLo: 5056 µg/kg (16D pre) [Journal of Reproduction and Fertility. (Biochemical Soc. Book Depot, POB 32, Commerce Way, Colchester, Essex CO2 8HP, UK) V.1- 1960- v. 56, p. 675, 1979 (JRPFA4)]
Effects on developmental toxicity
Description of key information
Androstendione is an endogenous intermediate in steroid hormone synthesis and as such an endogenous precursor of testosterone and estrone, which can be metabolized to estradiol. Exposure during pregnancy may lead to signs of masculinization in the sex organs of a female child. If taken by nursing women androstendione may reach into the mother's milk and thus impair the development of the infant.
Link to relevant study records
- Endpoint:
- developmental toxicity
- Type of information:
- experimental study
- Adequacy of study:
- key study
- Reliability:
- 2 (reliable with restrictions)
- Rationale for reliability incl. deficiencies:
- study well documented, meets generally accepted scientific principles, acceptable for assessment
- Principles of method if other than guideline:
- - Principle of test:
Thirty-day old female rats received corn oil or androstenedione (in corn oil) at one of four concentrations (5.0, 10.0, 30.0 or 60.0 mg/kg body weight) by gavage for two weeks prior to mating, during the mating period and until gestation day (GD) 19. Caesarean sections were performed on GD 20.
- Parameters analysed / observed:
number of corpora lutea, the number of implantation sites, and the number and position of resorption sites and fetuses (dead or alive); gravid uterus weight;
viable fetuses examined individually for any gross external morphological effects, sex, weight, crown-rump length, and anogenital distance, any externally visible abnormalities, skeletal anomalies, soft-tissue anomalies;
serum hormones levels: Androstenedione, Estradiol, LH, FSHTestosterone, Progesterone - GLP compliance:
- yes
- Limit test:
- no
- Specific details on test material used for the study:
- SOURCE OF TEST MATERIAL
- Source: Steraloids, Newport, RI
- Purity: >99% - Species:
- rat
- Strain:
- other: CD-CRL:CD-BR, VAF+
- Details on test animals or test system and environmental conditions:
- TEST ANIMALS
- Source: Charles River Laboratories, Inc. (Wilmington, MA)
female (n = 250; 49 days old; 150–175 g)
male (n = 91; 56 days old; 175–200 g)
- Housing:
females: singly during the pre-mating dosing period and from GD 0 until GD 20
- Diet (e.g. ad libitum): Purina Rodent Chow 5002M (Purina Mills, Inc., Richmond, IN), ad libitum
males: singly, except during mating period
mating period: two female rats + one male rat
- Water (e.g. ad libitum): ad libitum
- Acclimation period: approx 1 wk
ENVIRONMENTAL CONDITIONS
- Temperature (°C): 64–79 °F
- Humidity (%): 40–70%
- Photoperiod (hrs dark / hrs light): 12/12
- Route of administration:
- oral: gavage
- Vehicle:
- corn oil
- Details on exposure:
- PREPARATION OF DOSING SOLUTIONS:
Dosing solutions were stable for >35 days as determined by HPLC analysis. All solutions of androstenedione were prepared and used according to the results of the stability tests. The dosing solutions were only utilized after HPLC analysis confirmed that the solutions were within the prescribed concentrations (±10%).
VEHICLE
- Amount of vehicle (if gavage):
0.3 ml corn oil /100 g bw: control, 5.0, 10.0 or 30.0 mg/kg bw/d dose groups
0.6 mL/100 g bw: double dose control or ‘‘00’’ control, 60 mg/kg bw/d dose group - Analytical verification of doses or concentrations:
- yes
- Details on mating procedure:
- - Impregnation procedure: cohoused
- M/F ratio per cage: 1:2
- Length of cohabitation: 15 h/day, 5 days/week for up to 3 weeks or until mating occurred
-females that did not mate at the end of the week were re-mated with a different randomly selected
- At the end of the three-week mating period, females that did not mate (n = 3) were necropsied.
- Proof of pregnancy: sperm in vaginal smear referred to as day 0 of pregnancy - Duration of treatment / exposure:
- - males: not exposed
- females: 2 weeks prior to mating, during the mating period (up to 3 weeks) and from GD 0 through GD 19 - Frequency of treatment:
- daily
- Dose / conc.:
- 5 mg/kg bw/day (actual dose received)
- Dose / conc.:
- 10 mg/kg bw/day (actual dose received)
- Dose / conc.:
- 30 mg/kg bw/day (actual dose received)
- Dose / conc.:
- 60 mg/kg bw/day (actual dose received)
- No. of animals per sex per dose:
- The distribution of the animals among 0 control, 00 control, 5, 10, 30 and 60 mg/kg dose groups were 39, 29, 39, 29, 33 and 40, respectively.
- Control animals:
- yes, concurrent vehicle
- Maternal examinations:
- Estrous cyclicity was evaluated in 20 randomly selected animals from the 30 mg/kg and 60 mg/kg treatment groups monitored daily during the two week pre-mating exposure period
- Ovaries and uterine content:
- - corpora lutea, number of implantation sites, and number and position of resorption sites and fetuses (dead or alive)
- gravid uterus was removed in toto and weighed - Blood sampling:
- Blood was collected from the inferior vena cava of all pregnant females, serum hormone (Androstenedione, Estradiol, LH, FSH, Testosterone, Progesterone) and gonadotrophin levels were determined by radioimmunoassay
- Fetal examinations:
- gross external morphological effects
anogenital distance
skeletal anomalies
soft-tissue anomalies - Statistics:
- A p value of =0.05 was considered statistically significant. For the parameters feed and fluid consumption, number of corpora lutea, implants, alive, males and females alive and estrous cyclicity data, an Analysis of Variance (ANOVA) followed by a protected least significance difference (LSD) test (one-tail, if ANOVA p < 0.05) was used to compare the two control groups as well as each control group with their respective treatment group(s). For the parameters implantation efficiency and percent early, late, and total (early + late) resorptions, the data were transformed using a Freeman–Tukey Arc–Sine Transformation followed by an ANOVA and a protected LSD test as discussed above.
An Analysis of Covariance (ANCOVA) followed by a protected LSD (two-tail, if the ANCOVA p < 0.05) test was used to compare the control with each treated group for the parameters adult organ weights, and mean body weight gain and gravid uterine weight of pregnant females. The ANCOVA adjusted the body weight gain
and the gravid weight by day 0 dam weight, and the organ weight by the final dam weight. For both the fetal weight and crown rump measurements, a Nested ANOVA followed by a protected LSD test (p < 0.05) was used to compare the control and treated groups. A Fisher's Exact Test was used to compare the treated groups with the control for the incidence of specific soft-tissue variations in fetuses, and clinical external signs in female rats and day 20 fetuses. - Dose descriptor:
- NOAEL
- Effect level:
- 30 mg/kg bw/day (actual dose received)
- Based on:
- test mat.
- Basis for effect level:
- endocrine findings
- Abnormalities:
- no effects observed
- Dose descriptor:
- NOAEL
- Effect level:
- 60 mg/kg bw/day (actual dose received)
- Based on:
- test mat.
- Sex:
- male/female
- Basis for effect level:
- other: no specific effect on fetal parameters
- Abnormalities:
- no effects observed
- Developmental effects observed:
- no
- Executive summary:
Thirty-day old female rats received corn oil or androstenedione (in corn oil) at one of four concentrations (5.0, 10.0, 30.0 or 60.0 mg/kg body weight) by gavage for two weeks prior to mating, during the mating period and until gestation day (GD) 19. Caesarean sections were performed on GD 20. No dose related changes were observed in serum androstenedione, estradiol, LH, FSH, testosterone or progesterone. A statistically significant decrease in estrous cycle length was observed in the 60.0 mg/kg dose group only. Feed and fluid consumption, mean body weight gain, organ weight and fetal parameters were not affected by androstenedione treatment. At the doses given, androstenedione had no specific effect on the development of individual bones or soft tissues.
- Endpoint:
- developmental toxicity
- Type of information:
- experimental study
- Adequacy of study:
- key study
- Reliability:
- 2 (reliable with restrictions)
- Rationale for reliability incl. deficiencies:
- study well documented, meets generally accepted scientific principles, acceptable for assessment
- Principles of method if other than guideline:
- - Principle of test: Thirty-day old rats received corn oil alone or androstenedione (in corn oil) at one of four concentrations (0, 1.0, 5.0, 10.0 or 30.0 mg/kg body weight) by gavage for two weeks prior to mating, during the mating period and throughout gestation
- Parameters analysed / observed: Feed and fluid consumption, Body weight, estrous cycle, number of corpora lutea, the number of implantation sites, and the number and position of resorption sites and fetuses (dead or alive), gravid uterus weight;
fetuses: sex, weight, crown-rump length, anogenital distance, external, skelatal, visceral abnormalities - GLP compliance:
- not specified
- Specific details on test material used for the study:
- obtained from Steraloids, Newport, RI
>99% pure - Species:
- rat
- Strain:
- other: CD-CRL: CD-BR
- Details on test animals or test system and environmental conditions:
- TEST ANIMALS
- Source: Charles River Laboratories, Inc. (Wilmington, MA)
- Females nulliparous and non-pregnant: yes
- female (n=60; 49 days old; 150–175 g), male (n=30; 56 days old; 175–200 g)
- Housing:
acclimation period: singly
mating period: two female rats co-habitated with a single male
- Diet (e.g. ad libitum): Purina Rodent Chow 5002 (Purina Mills, Inc., Richmond,
IN), ad libitum
- Water (e.g. ad libitum): ad libitum
- Acclimation period: approx. 1 wk
ENVIRONMENTAL CONDITIONS
- Temperature (°C): 64–79 F
- Humidity (%): 40-70%
- Photoperiod (hrs dark / hrs light): 12/12 - Route of administration:
- oral: gavage
- Vehicle:
- corn oil
- Details on exposure:
- PREPARATION OF DOSING SOLUTIONS:
Dosing solutions were stable for >35 days as determined by HPLC analysis. All solutions of androstenedione were prepared and used according to the results of the stability tests. The dosing solutions were not utilized until HPLC analysis confirmed the solutions were within the prescribed concentrations (±10%). - Analytical verification of doses or concentrations:
- yes
- Details on mating procedure:
- - M/F ratio per cage: 1:2
- Length of cohabitation: 5 times per week for 3 weeks or until mating occurred
- Proof of pregnancy: sperm in vaginal smear referred to as day 0 of pregnancy
The females that did not mate at the end of the week were re-mated with a different
randomly selected male. At the end of the three week mating period, females that did not mate were necropsied. - Duration of treatment / exposure:
- females: 2 weeks prior to mating, during the mating period (up to 3 weeks) and days 0–20 of gestation
male rats were not treated and were only used as sires - Frequency of treatment:
- daily
- Dose / conc.:
- 1 mg/kg bw/day (actual dose received)
- Dose / conc.:
- 5 mg/kg bw/day (actual dose received)
- Dose / conc.:
- 10 mg/kg bw/day (actual dose received)
- Dose / conc.:
- 30 mg/kg bw/day (actual dose received)
- No. of animals per sex per dose:
- 12 females
- Control animals:
- yes, concurrent vehicle
- Maternal examinations:
- estrous cycle monitored during the 14-day pre-mating dosing period
- Ovaries and uterine content:
- - Gravid uterus weight: Yes
- Number of corpora lutea: Yes
- Number of implantations: Yes
- Number of early resorptions: Yes
- Number of late resorptions: Yes - Blood sampling:
- serum estradiol, estrone, testosterone and androstenedione levels
- Fetal examinations:
- - External examinations: Yes: all per litter
- Soft tissue examinations: Yes
- Skeletal examinations: Yes
- Anogenital distance - Statistics:
- For the parameters feed and fluid consumption, number of corpora lutea, implants, alive, males and females alive and estrous cyclicity data an Analysis of
Variance (ANOVA) followed by a protected least significance difference (LSD) test (one-tail, if ANOVA p<0.05) was used to compare the control with each
of the treated groups. For the parameters implant efficiency and percent early, late, and total (early+late) resorptions, the data were transformed using a Freeman-Tukey Arc-Sine Transformation followed by an ANOVA and a protected LSD test as discussed above.
An Analysis of Covariance (ANCOVA) followed by a protected LSD (two-tail, if the ANCOVA p<0.05) test was used to compare the control with each treated group for the parameters adult organ weights, and mean body weight gain and gravid uterine weight of pregnant females. The ANCOVA adjusted the body weight gain and the gravid weight by the Day 0 dam weight, and the organ weight by the final dam weight.
For both the fetal weight and crown rump measurements a Nested ANOVA followed by a protected LSD test (p<0.05) was used to compare the control and
treated groups.
A Fisher’s Exact Test was used to compare the treated groups with the control for the incidence of specific softtissue, sternebral, and skeletal variations in fetuses, and clinical signs in female rats and Day 20 fetuses. The of the treated groups for the number of litters with 1+, 2+, or 3+ soft-tissue, sternebral, and skeletal variations.
For the average number of fetuses per litter with 1+, 2+ or 3+ soft-tissue, sternebral, and skeletal variations the data were first transformed by a Freeman-Tukey Arc-Sine transformation. The transformed data were then analyzed using an ANOVA followed by a protected LSD test as explained above. A Nested ANOVA followed by a protected LSD test was used to compare the control and treated groups for the average number of ossified vertebrae in fetuses. - Details on maternal toxic effects:
- Dose-related increases in serum androstenedione levels were observed in all treated groups, and statistically significant increases were seen in the 5.0, 10.0 and 30.0 mg/kg dose groups. Dose related statistically significant increases in serum estrone levels were observed in all treated groups in comparison to the controls. A dose-related increase in serum estradiol levels was observed in all treated groups, and the increase was significant in the 10.0 and 30.0 mg/kg dose groups.
Serum testosterone levels were elevated in the 10 and 30 mg groups and significantly elevated in the 30.0 mg/kg dose group
A statistically significant decrease in the number of androstenedione treated animals having a regular estrous cycle was observed in the 10.0 and 30.0 mg/kg dose groups during the pre-mating period (Table 3). Only one animal from the 10.0 mg/kg dose group had a highly irregular cycle and at least one animal from each androstenedione dose group was acyclic.
Mean corpora lutea counts from androstenedione treated animals were indistinguishable from control values (Table 4). A slight (non-statistically significant) reduction in the number of implants, the average percent of early plus late deaths, and the mean number of viable fetuses and the mean number of viable male fetuses was observed in the 30.0 mg/kg dose group (Table 4). - Dose descriptor:
- NOAEL
- Effect level:
- 5 mg/kg bw/day (actual dose received)
- Basis for effect level:
- other: reproductive function (oestrous cycle)
- Abnormalities:
- no effects observed
- Reduction in number of live offspring:
- effects observed, treatment-related
- Description (incidence and severity):
- A slight (non-statistically significant) reduction in the mean number of viable fetuses and the mean number of viable male fetuses was observed in the 30.0 mg/kg dose group (Table 4).
- Changes in sex ratio:
- no effects observed
- Changes in litter size and weights:
- no effects observed
- Anogenital distance of all rodent fetuses:
- no effects observed
- External malformations:
- no effects observed
- Details on embryotoxic / teratogenic effects:
- Androstenedione exposure did not affect sternebral ossification, the incidence of fetal sternebal variations or the incidence of specific fetal skeletal variations.
A statistically significant increase in the number of fetuses with a moderately enlarged ureter at the kidney was observed in the 1.0 and 5.0 mg/kg dose groups, and slight non-statistically significant increases were observed in the 10.0 and 30.0 mg/kg dose groups (Table 5). The average number of soft-tissue variations per litter was similar in both control animals and the androstenedione treated animals (Table 5). Statistically significant differences in dam organ weights expressed per gram of body weight and dam organ weights expressed per gram of brain weight were not observed when values obtained for treated and control groups were compared. - Dose descriptor:
- NOAEL
- Effect level:
- 10 mg/kg bw/day (actual dose received)
- Sex:
- male/female
- Basis for effect level:
- reduction in number of live offspring
- Abnormalities:
- no effects observed
- Developmental effects observed:
- no
- Executive summary:
This study was conducted to characterize the effect of androstenedione on estrous cyclicity, mating behavior and fetal development.
Thirty-day old rats received corn oil alone or androstenedione (in corn oil) at one of four concentrations (0, 1.0, 5.0, 10.0 or 30.0 mg/kg body weight) by gavage for two weeks prior to mating, during the mating period and throughout gestation. Dose related increases in serum androstenedione, estradiol and estrone were observed in all androstenedione treated animals at gestation day 20. A statistically significant increase in serum testosterone concentration was observed in the 30 mg/kg dose group. Feed and fluid consumption were not affected by androstenedione treatment during the pre-mating or gestational periods, however a statistically significant decrease in the number of females with regular estrous cycles was observed in the 10.0 and 30.0 mg/kg dose groups. Exposure to androstenedione did not affect mean body weight gain during pre-mating or gestation. Slight not statistically significant reductions in the number of implants, number of viable fetuses and number of viable male fetuses were observed in the
30.0 mg/kg androstenedione group. Reductions were not observed in the number of corpora lutea. Fetal growth in terms of fetal weight, crown-rump length, anogenital distance and the number of external abnormalities was not affected by androstenedione exposure. At the doses given, androstenedione had no specific effect on the development of individual bones, including sternebrae.
Dose related effects of androstenedione were not observed on the development of soft tissues. A statistically significant increase in moderately enlarged ureter at the kidney was observed in both the 1.0 and 5.0 mg/kg dose groups. Organ weights (expressed per gram of body weight or per gram of brain weight) were not affected by androstenedione treatment.
Referenceopen allclose all
Table 1: Serum endocrine parameters (mean ± SEM) from day 20 pregnant rats a
| Dose levels (mg/kg) | |||||
| 0 (19) | 00 (21) | 5.0 (25) | 10.0 (27) | 30.0 (24) | 60.0 (27) |
Androstenedione b | 1.67 ± 0.14 | 1.65 ± 0.16 | 1.53 ± 0.10 | 1.64 ± 0.11 | 1.75 ± 0.10 | 1.67 ± 0.11 |
Estradiol c | 61.68 ± 3.51 | 50.60 ± 3.96 | 56.09 ± 4.30 | 54.29 ± 3.59 | 62.61 ± 4.51 | 57.08 ± 3.24 |
LH d,b | 1.06 ± 0.07 | 1.12 ± 0.04 | 1.28 ± 0.10 | 1.30 ± 0.15 | 1.08 ± 0.06 | 1.07 ± 0.07 |
FSH b | 5.92 ± 0.38 | 6.13 ± 0.31 | 6.53 ± 0.32 | 6.26 ± 0.27 | 6.53 ± 0.37 | 5.81 ± 0.26 |
Testosterone b | 0.47 ± 0.06 | 0.59 ± 0.08 | 0.48 ± 0.06 | 0.48 ± 0.04 | 0.52 ± 0.06 | 0.46 ± 0.05 |
Progesterone b | 16.68 ± 1.99 | 16.15 ± 2.50 | 15.57 ± 1.78 | 15.53 ± 1.80 | 17.04 ± 1.79 | 16.82 ± 1.34 |
( ) = number of litters.
a If the p value is not given then p > 0.10.
b Data expressed in ng/ml.
c Data expressed in pg/ml.
d Data transformed using a log transformation.
Table 2: Estrous cycle measurements during 14-day pre-mating period (day, mean ± SEM)
| Dose levels (mg/kg) | |||
| 0 (20) | 00 (20) | 30.0 (20) | 60.0 (20) |
Regular cycle (4–5 days) | 2.05 ± 0.17 | 2.20 ± 0.17 | 2.05 ± 0.17 | 1.65 ± 0.18 |
Irregular cycle (2,3,6–10 days) | 0.25 ± 0.12 | 0.25 ± 0.14 | 0.10 ± 0.07 | 0.30 ± 0.15 |
Highly irregular cycle (11–13 days) | 0.00 ± 0.00 | 0.00 ± 0.00 | 0.05 ± 0.05 | 0.00 ± 0.00 |
Acyclic (14 days) | 0.00 ± 0.00 | 0.00 ± 0.00 | 0.00 ± 0.00 | 0.00 ± 0.00 |
Number of estrous stages observed | 3.30 ± 0.13 | 3.45 ± 0.15 | 3.20 ± 0.14 | 2.85 ± 0.15* |
( ) = number of animals per group. *Indicates statistically significant difference from the ‘‘00’’ control group; p </= 0.05.
Table 3: Mean feed and fluid consumption and body weight gain during pre-mating (days 0–14) and gestation (days 0–20) a
| Dose levels (mg/kg) | |||||
| 0 | 00 | 5.0 | 10.0 | 30.0 | 60.0 |
Feed consumption (g ± SEM) | ||||||
0–14 b | 229.3 ± 2.7 | 207.4 ± 2.3 | 231.7 ± 3.0 | 225.0 ± 2.9 | 229.2 ± 2.7 | 211.9 ± 1.7 |
0–20 c | 399.2 ± 6.0 | 344.7 ± 6.2 | 396.9 ± 6.2 | 397.3 ± 7.0 | 402.6 ± 5.8 | 358.6 ± 4.3 |
Fluid consumption (ml ± SEM) | ||||||
0–14 b | 387.8 ± 9.7 | 376.0 ± 10.6 | 375.0 ± 10.1 | 356.5 ± 10.9 | 390.8 ± 8.1 | 363.7 ± 7.0 |
0–20 c | 727.7 ± 16.8 | 650.9 ± 24.0 | 698.5 ± 17.4 | 711.3 ± 24.6 | 732.3 ± 18.8 | 655.3 ± 14.2 |
Mean body weight gain (g ± SEM) | ||||||
0–14 b, d | 34.4 ± 1.7 | 31.8 ± 1.4 | 34.1 ± 1.5 | 34.5 ± 1.7 | 37.5 ± 1.6 | 38.6 ± 1.3 |
0–20 c, d | 138.4 ± 4.6 | 132.0 ± 7.1 | 133.6 ± 4.3 | 134.5 ± 4.7 | 134.2 ± 5.2 | 131.9 ± 4.7 |
a If p value not given p > 0.10.
b n = 47, 38, 39, 30, 41 and 57 animals for the 0, 00, 5.0, 10.0, 30.0 and 60 mg/kg dose groups, respectively.
c n = 39, 29, 39, 29, 33 and 40 animals for the 0, 00, 5.0, 10.0, 30.0 and 60 mg/kg dose groups, respectively.
d Total weight gain minus gravid uterine weight.
Table 4: Analysis of maternal and reproductive necropsy findings a
Dose level (mg/kg) | ||||||
0 (39) | 00 (29) | 5.0 (39) | 10.0 (29) | 30.0 (33) | 60.0 (40) | |
No. (%) of pregnant females | ||||||
37 (95) | 27 (93) | 38 (97) | 28 (97) | 32 (97) | 38 (95) | |
Corpora lutea (Mean ± SEM) | ||||||
16.27 ± 0.29 | 16.19 ± 0.52 | 16.03 ± 0.46 | 16.86 ± 0.39 | 16.03 ± 0.41 | 16.13 ± 0.38 | |
Implants/litter (Mean ± SEM) | ||||||
15.27 ± 0.30 | 14.89 ± 0.70 | 14.03 ± 0.66 | 14.86 ± 0.58 | 14.44 ± 0.52 | 14.21 ± 0.57 | |
Implantation efficiency (%, Mean ± SEM) | ||||||
94.14 ± 1.34 | 90.47 ± 3.45 | 86.88 ± 3.09 | 88.12 ± 2.91 | 89.63 ± 2.56 | 87.63 ± 3.04 | |
Early + late deaths/litter (%, Mean ± SEM) | ||||||
3.96 ± 0.84 | 6.50 ± 3.69 | 2.55 ± 0.69 | 7.14 ± 2.10 | 9.53 ± 3.21 | 4.20 ± 0.89 | |
Viable fetuses/litter (Mean ± SEM) | ||||||
14.68 ± 0.32 | 14.44 ± 0.73 | 13.61 ± 0.62 | 13.79 ± 0.62 | 13.44 ± 0.61 | 13.61 ± 0.56 | |
Total number of fetuses (litters) | ||||||
Male | 276 (37) | 195 (26) | 273 (38) | 176 (28) | 221 (31) | 264 (38) |
Female | 267 (37) | 195 (26) | 244 (38) | 210 (28) | 209 (31) | 253 (37) |
Viable fetuses/litter (Mean ± SEM) | ||||||
Male | 7.46 ± 0.32 | 7.22 ± 0.53 | 7.18 ± 0.43 | 6.29 ± 0.51 | 6.91 ± 0.44 | 4.50 ± 0.52 |
Female | 7.22 ± 0.39 | 6.95 ± 0.39 | 6.42 ± 0.37 | 7.50 ± 0.49 | 6.53 ± 0.42 | 7.10 ± 0.62 |
Anogenital distance (Mean ± SEM) | ||||||
Male | 3.40 ± 0.02 | 3.40 ± 0.03 | 3.40 ± 0.02 | 3.34 ± 0.03 | 3.38 ± 0.02 | 3.45 ± 0.02 |
Female | 1.68 ± 0.01 | 1.73 ± 0.02 | 1.69 ± 0.01 | 1.66 ± 0.02 | 1.74 ± 0.02 | 1.76 ± 0.01 |
Sex distribution (%) | ||||||
Male | 50.83 | 50 | 52.8 | 45.6 | 51.4 | 51.06 |
Female | 49.17 | 50 | 47.2 | 44 | 48.6 | 48.94 |
Fetal body weight (g, Mean ± SEM) | ||||||
Males | 3.80 ± 0.02 | 3.70 ± 0.02 | 3.76 ± 0.02 | 3.75 ± 0.03 | 3.74 ± 0.03 | 3.73 ± 0.03 |
Females | 3.63 ± 0.02 | 3.54 ± 0.02 | 3.56 ± 0.02 | 3.56 ± 0.03 | 3.62 ± 0.02 | 3.59 ± 0.02 |
Fetal crown-rump length (cm, Mean ± SEM) | ||||||
Males | 4.02 ± 0.01 | 3.99 ± 0.01 | 4.01 ± 0.01 | 4.01 ± 0.01 | 4.00 ± 0.01 | 3.99 ± 0.01 |
Females | 3.94 ± 0.01 | 3.92 ± 0.01 | 3.91 ± 0.01 | 3.93 ± 0.01 | 3.94 ± 0.01 | 3.91 ± 0.01 |
No. runts (litters with runts) | ||||||
Males | 1 (1) | 2 (2) | 1 (1) | 2 (2) | 2 (2) | 5 (5) |
Females | 3 (3) | 0 (0) | 2 (2) | 2 (2) | 0 (0) | 4 (4) |
a If the p value is not given then p > 0.10.
Table 5: Representative incidence of specific fetal soft-tissue variations *
Dose level (mg/kg) | 0 | 0 | 5 | 10 | 30 | 60 |
No. fetuses (litters) examined | 236 (35) | 196 (26) | 225 (36) | 194 (28) | 214 (31) | 232 (37) |
Hydroureter, severe | 6 (5) | 7 (5) | 5 (5) | 10 (6) | 4 (4) | 10 (7) |
Hydroureter, moderate | 0 (0) | 24 (12) | 0 (0) | 0 (0) | 0 (0) | 13 (11) |
Enlarged renal pelvis, moderate | 6 (3) | 8 (7) | 14 (8) | 8 (5) | 12 (10)* | 12 (9) |
Enlarged ureter at kidney, severe | 12 (7) | 16 (8) | 11 (7) | 10 (6) | 4 (4) | 9 (7) |
Enlarged ureter at kidney, moderate | 16 (12) | 15 (8) | 23 (14) | 20 (12) | 17 (13) | 18 (14) |
Kidney, ectopic | 1 (1) | 0 (0) | 1 (1) | 1 (1) | 1 (1) | 3 (3) |
Anophthalmia | 0 (0) | 0 (0) | 0 (0) | 0 (0) | 0 (0) | 1 (1) |
( ) = number of litters.
*p 6 0.05.
Table 6A: Absolute organ weights for selected maternal organs (g, mean ± SEM)
Dose level (mg/kg) | ||||||
0 (31) | 00 (26) | 5.0 (33) | 10.0 (28) | 30.0 (32) | 60.0 (33) | |
Heart | 0.913 ± 0.016 | 0.882 ± 0.014 | 0.909 ± 0.011 | 0.902 ± 0.015 | 0.892 ± 0.015 | 0.942 ± 0.034 |
Liver | 14.531 ± 0.241 | 14.282 ± 0.238 | 13.987 ± 0.280 | 14.215 ± 0.288 | 14.237 ± 0.276 | 14.647 ± 0.243 |
Spleen | 0.710 ± 0.065 | 0.609 ± 0.016 | 0.621 ± 0.023 | 0.647 ± 0.019 | 0.611 ± 0.014 | 0.604 ± 0.012 |
Adrenal | ||||||
Rt. | 0.035 ± 0.002 | 0.033 ± 0.001 | 0.035 ± 0.001 | 0.032 ± 0.001 | 0.032 ± 0.001 | 0.030 ± 0.001 |
Lft. | 0.037 ± 0.002 | 0.033 ± 0.001 | 0.036 ± 0.001 | 0.033 ± 0.001 | 0.032 ± 0.001 | 0.030 ± 0.001 |
Both | 0.072 ± 0.003 | 0.066 ± 0.002 | 0.071 ± 0.002 | 0.065 ± 0.002 | 0.064 + 0.002 | 0.060 ± 0.002 |
Ovary | ||||||
Rt. | 0.077 ± 0.003 | 0.072 ± 0.002 | 0.074 ± 0.002 | 0.070 ± 0.002 | 0.076 ± 0.003 | 0.074 ± 0.003 |
Lft. | 0.072 + 0.002 | 0.071 ± 0.003 | 0.070 ± 0.0021 | 0.072 ± 0.002 | 0.071 ± 0.002 | 0.070 ± 0.003 |
Both | 0.150 + 0.004 | 0.143 ± 0.003 | 0.144 ± 0.0042 | 0.142 ± 0.003 | 0.147 ± 0.004 | 0.144 ± 0.005 |
Brain | 1.898 ± 0.014 | 1.879 ± 0.021 | 1.888 ± 0018 | 1.925 ± 0.016 | 1.910 ± 0.016 | 1.889 ± 0.016 |
( ) = number of organs examined.
Table 6B: Organ to brain weight ratios for selected maternal organs (g, mean ± SEM)
Dose level (mg/kg) | ||||||
0 (31) | 00 (26) | 5.0 (33) | 10.0 (28) | 30.0 (32) | 60.0 (33) | |
Heart | 0.481 ± 0.008 | 0.470 ± 0.008 | 0.482 ± 0.006 | 0.469 ± 0.008 | 0.468 ± 0.008 | 0.498 ± 0.016 |
Liver | 7.659 ± 0.144 (25)a | 7.625 ± 0.155 | 7.458 ± 0.156 | 7.390 ± 0.150 | 7.463 ± 0.150 (26)a | 7.776 ± 0.133 (27)a |
Spleen | 0.373 ± 0.032 | 0.325 ± 0.008 | 0.392 ± 0.012 | 0.337 ± 0.011 | 0.320 ± 0.006 | 0.320 ± 0.006 |
Adrenal | ||||||
Rt. | 0.018 ± 0.001 | 0.018 ± 0.001 | 0.018 ± 0.001 | 0.017 ± 0.001 | 0.017 ± 0.001 | 0.016 ± 0.001** |
Lft. | 0.019 ± 0.001 | 0.018 ± 0.001 | 0.019 ± 0.001 | 0.017 ± 0.001* | 0.017 ± 0.001* | 0.016 ± 0.001** |
Both | 0.037 ± 0.001 | 0.036 ± 0.001 | 0.037 ± 0.001 | 0.034 ± 0.001* | 0.034 + 0.001* | 0.032 ± 0.001** |
Ovary | ||||||
Rt. | 0.041 ± 0.001 | 0.038 ± 0.001 | 0.039 ± 0.002 | 0.037 ± 0.001 | 0.040 ± 0.002 | 0.039 ± 0.002 |
Lft. | 0.038 + 0.001 | 0.038 ± 0.002 | 0.037 ± 0.001 | 0.037 ± 0.001 | 0.0378 ± 0.001 | 0.037 ± 0.002 |
Both | 0.079 + 0.002 | 0.076 ± 0.002 | 0.076 ± 0.002 | 0.074 ± 0.002 | 0.077 ± 0.002 | 0.076 ± 0.002 |
( ) = number of organs examined.
* Significantly different than the ‘‘0’’ control group, p </= 0.05.
** Significantly different than the ‘‘00’’ control group, p </= 0.05.
a Indicates that six livers were transferred to another protocol.
Table 1: Mean serum endocrine parameters (±SEM) from day 20 pregnant rats
Dose (mg/kg) | 0 | 1.0 | 5.0 | 10.0 | 30.0 |
No. Dams | 11 | 11 | 10 | 11 | 10 |
Androstenedione (ng/ml) | 1.27±0.15 | 1.36±0.14 | 1.83±0.20** | 2.19±0.25** | 4.71±0.41**** |
Estradiol (pg/ml) | 65.86±4.94 | 77.54±7.72 | 79.89±7.12 | 90.63±6.43* | 128.34±10.86**** |
Estrone (pg/ml) | 33.02±4.92 | 42.37±3.72* | 55.97±6.24** | 62.26±7.05**** | 110.79±13.82**** |
Testosterone (ng/ml | 0.21±0.03 | 0.18±0.04 | 0.19±0.03 | 0.27±0.03 | 0.70±0.11**** |
Asterisks indicate significant difference from controls (* p</=0.05; ** p</=0.01; *** p</=0.001; **** p</=0.0001).
Table 2: Mean feed and fluid consumption and body weight during the pre-mating period
Days | Dose (mg/kg) |
|
|
|
|
0 | 1.0 | 5.0 | 10.0 | 30.0 | |
Feed Consumption (g±SEM) | |||||
0–14a | 209.9±3.9 | 205.2±4.3 | 201.6±4.1 | 214.2±6.0 | 219.2±5.4 |
0–20b
| 401.3±7.1 | 399.6±14.0 | 400.0±7.4 | 408.3±8.7 | 400.9±11.4 |
Fluid Consumption (ml±SEM) | |||||
0–14a
| 376.4±18.1 | 388.3±26.5 | 369.2±17.6 | 415.8±23.7 | 404.7±15.1 |
0–20b
| 642.5±25.9 | 684.3±34.7 | 644.4±24.0 | 727.7±30.4 | 656.2±19.1 |
Terminal Body Weight (g±SEM) | |||||
14a
| 225.4±3.7 | 223.2±3.5 | 222.7±3.1 | 230.6±5.1 | 236.6±4.5 |
20b
| 364.1±5.3 | 361.5±9.9 | 365.4±6.1 | 368.5±9.7 | 366.3±8.2 |
Mean Body Weight Gain (g±SEM) | |||||
0–14a | 37.4±3.5 | 32.7±2.6 | 33.4±3.5 | 40.6±2.8 | 45.8±3.0 |
0–20b | 136.2±2.0 | 139.3±7.2 | 138.8±4.7 | 134.2±6.8 | 125.7±6.2 |
Adjusted Weight Gain (g±SEM) | |||||
20b,c | 56.4±3.3 | 58.2±4.0 | 59.7±4.0 | 57.8±3.5 | 57.1±7.2 |
a n=12 animals per group.
b n=11, 11, 10, 11, 10 animals per group for the 0.0, 1.0, 5.0, 10.0 and 30.0 mg/kg body weight dose groups.
c Total weight gain minus gravid uterine weight.
Table 3: Summary of estrous cycle measurements collected for 14 consecutive days prior to mating for female rats treated with androstenedione
Dose Level (mg/kg) | 0 | 1.0 | 5.0 | 10.0 | 30.0 |
No. Dams | 12 | 12 | 12 | 12 | 12 |
Regular Cycle (4-5 Days) | 10 | 8 | 9 | 5* | 5* |
Irregular Cycle (3, 6–10 Days) | 2 | 3 | 2 | 5 | 5 |
Highly Irregular Cycle (11–13 Days) | 0 | 0 | 0 | 1 | 0 |
Acyclic (14 Days) | 0 | 1 | 1 | 1 | 2 |
Total No. Estrous Cycles | 42 | 34 | 34 | 31 | 28 |
Mean No. Estrous Cycles (Mean±SEM) | 3.6±0.2
| 2.9±0.2*
| 2.9±0.2*
| 2.9±0.1**
| 2.4±0.2** |
Asterisks indicate significant difference from controls (* p</=0.05; ** p</=0.01).
Table 4: Analysis of maternal and reproductive autopsy findings
Dose Level (mg/kg) | 0 | 1.0 | 5.0 | 10.0 | 30.0 |
No of pregnant females | 11 | 11 | 10 | 11 | 10 |
Corpora Lutea (Mean±SEM) | 14.45±0.41 | 14.91±0.44 | 15.40±0.72 | 14.91±0.49 | 14.60±0.54 |
Implants (Mean±SEM) | 14.00±0.50 | 13.82±1.02 | 14.20±0.76 | 13.45±1.11 | 12.70±1.03 |
Implantation Efficiency | 96.84±2.00 | 92.18±5.74 | 93.11±4.36 | 90.08±6.97 | 86.94±6.43 |
Av. Percent early / late deaths/litter (%, Mean±SEM) | 4.43±1.73 | 2.92±1.57 | 5.17±2.25 | 3.60±1.37 | 7.90±3.03 |
Viable Fetuses (Mean±SEM) | 13.36±0.51 | 13.36±0.97 | 13.50±0.86 | 12.91±1.05 | 11.60±0.97 |
Male | 6.45±0.37 | 6.36±0.72 | 6.30±0.73 | 6.36±0.59 | 4.50±0.52 |
Female | 6.91±0.65 | 7.00±0.74 | 7.20±0.55 | 6.55±0.68 | 7.10±0.62 |
Sex Distribution (%) | |||||
Male | 48.30 | 47.62 | 46.67 | 49.30 | 38.79 |
Female | 51.70 | 52.38 | 53.33 | 50.70 | 61.21 |
Fetal body weight (g, Mean±SEM) | |||||
Males | 3.99±0.03 | 4.06±0.04 | 3.87±0.04 | 3.91±0.05 | 3.92±0.06 |
Females | 3.81±0.03 | 3.83±0.03 | 3.71±0.03 | 3.73±0.04 | 3.63±0.06 |
Fetal crown-rump length (cm, Mean±SEM) | |||||
Males | 4.1±0.01 | 4.2±0.02 | 4.1±0.01 | 4.1±0.02 | 4.1±0.02 |
Females | 4.0±0.01 | 4.0±0.01 | 4.0±0.01 | 4.0±0.01 | 4.0±0.02 |
No. runts (litters with runts) | |||||
Males) | 0(0) | 0(0) | 0(0) | 2(1) | 1(1) |
Females | 0(0) | 0(0) | 0(0) | 1(1) | 2(2) |
Table 5: Incidence of specific fetal soft-tissue variations
Dose Level (mg/kg) | 0 | 1.0 | 5.0 | 10.0 | 30.0 |
No. fetuses (litters) examined | 76(11) | 73(11) | 69(10) | 70(11) | 57(10) |
Hemorrhage, internal | 1(1) | 1(1) | - | - | - |
Hydroureter, severe | 1(1) | 8(4) | 4(4) | 2(2) | 4(3) |
Hydroureter, moderate | 5(4) | 13(6) | 15(8) | 8(5) | 11(7) |
Enlarged renal pelvis, severe | - | - | - | - | - |
Enlarged renal pelvis, moderate | 1(1) | - | 1(1) | - | 1(1) |
Enlarged ureter at kidney, severe | 2(2) | 7(4) | 3(2) | 3(2) | 5(3) |
Enlarged ureter at kidney, moderate | 5(2) | 15(7)* | 17(9)** | 9(6) | 7(6) |
Kidney, ectopic | 3(3) | - | - | - | - |
Cleft Palate | 1(1) | - | - | - | - |
Undescended Testicle | - | - | - | - | 1(1) |
Number of litters involved in parentheses. Asterisks indicate: * p</=0.05; ** p</=0.01
Effect on developmental toxicity: via oral route
- Endpoint conclusion:
- no study available
Effect on developmental toxicity: via inhalation route
- Endpoint conclusion:
- no study available
Effect on developmental toxicity: via dermal route
- Endpoint conclusion:
- no study available
Additional information
Androstendione is an endogenous intermediate in steroid hormone synthesis and as such an endogenous precursor of testosterone and estrone, which can be metabolized to estradiol. Exposure during pregnancy may lead to signs of masculinization in the sex organs of a female child. If taken by nursing women androstendione may reach into the mother's milk and thus impair the development of the infant.
For an assessment of steroid hormones see also the argumentation for steroid hormones related to the Technical Rule for Hazardous Substances 905, which was elaborated by the German Committee on Hazardous Substances (AGS) and published by the German Federal Ministry of Labour and Social Affairs (version of 2008/2005/1999, only available in german, (http://www.baua.de/de/Themen-von-A-Z/Gefahrstoffe/TRGS/Begruendungen-905-906.html). In this argumentation 73 steroid hormones or precursors of steroid hormones were each allocated to one of seven hormone classes based on their predominant pharmacological activity (i.e. androgenic, mild androgenic, anabolic, estrogenic, gestagenic, mild gestagenic or glucocorticoide), and recommendations for their classification were elaborated.
A study was conducted to characterize the effect of androstenedione on estrous cyclicity, mating behavior and fetal development.
Thirty-day old rats received corn oil alone or androstenedione (in corn oil) at one of four concentrations (0, 1.0, 5.0, 10.0 or 30.0 mg/kg body weight) by gavage for two weeks prior to mating, during the mating period and throughout gestation. Dose related increases in serum androstenedione, estradiol and estrone were observed in all androstenedione treated animals at gestation day 20. A statistically significant increase in serum testosterone concentration was observed in the 30 mg/kg dose group. Feed and fluid consumption were not affected by androstenedione treatment during the pre-mating or gestational periods, however a statistically significant decrease in the number of females with regular estrous cycles was observed in the 10.0 and 30.0 mg/kg dose groups. Exposure to androstenedione did not affect mean body weight gain during pre-mating or gestation. Slight not statistically significant reductions in the number of implants, number of viable fetuses and number of viable male fetuses were observed in the
30.0 mg/kg androstenedione group. Reductions were not observed in the number of corpora lutea. Fetal growth in terms of fetal weight, crown-rump length, anogenital distance and the number of external abnormalities was not affected by androstenedione exposure. At the doses given, androstenedione had no specific effect on the development of individual bones, including sternebrae.
Dose related effects of androstenedione were not observed on the development of soft tissues. A statistically significant increase in moderately enlarged ureter at the kidney was observed in both the 1.0 and 5.0 mg/kg dose groups. Organ weights (expressed per gram of body weight or per gram of brain weight) were not affected by androstenedione treatment.
In a second study thirty-day old female rats received corn oil or androstenedione (in corn oil) at one of four concentrations (5.0, 10.0, 30.0 or 60.0 mg/kg body weight) by gavage for two weeks prior to mating, during the mating period and until gestation day (GD) 19. Caesarean sections were performed on GD 20. No dose related changes were observed in serum androstenedione, estradiol, LH, FSH, testosterone or progesterone. A statistically significant decrease in estrous cycle length was observed in the 60.0 mg/kg dose group only. Feed and fluid consumption, mean body weight gain, organ weight and fetal parameters were not affected by androstenedione treatment. At the doses given, androstenedione had no specific effect on the development of individual bones or soft tissues.
Additional data on developmental toxicity are cited in RTECS database (April 2013):
The daily subcutaneous administration of androstendione to hamsters on day 1-4 of pregnancy results in pre-implantation mortality (e.g., reduction in number of implants per female; total number of implants per corpora lutea); TDLo: 35 mg/kg (1-4D preg) [Endocrinology (Baltimore). (Williams and Wilkins Co., 428 E. Preston St., Baltimore, MD 21203) V.1- 1917- v. 80, p. 1152, 1967 (ENDOAO)]
The daily subcutaneous administration of androstendione to hamsters on day 1 -4 of pregnency results in maternal effects in ovaries, and fallopian tubes not further specified; TDLo: 17500 ug/kg (1-4D preg) [Endocrinology (Baltimore). (Williams and Wilkins Co., 428 E. Preston St., Baltimore, MD 21203) V.1- 1917- v. 80, p. 1152, 1967 (ENDOAO)]
Androstendione is administered subcutaneous to hamsters on day 1-4 of pregnancy. This leads in unspecified maternal effects of uterus, cervix and vagina; TDLo: 70 mg/kg (1-4D preg) [Endocrinology (Baltimore). (Williams and Wilkins Co., 428 E. Preston St., Baltimore, MD 21203) V.1- 1917- v. 80, p. 1152, 1967 (ENDOAO)]
Adrostendion is administered subcutaneous to rats on day 2-5 of pregnancy leading to maternal effects in uterus, cervix and vagina as well as pre-implantation mortality (e.g., reduction in number of implants per female; total number of implants per corpora lutea) and further unspecified effects on fertility; TDLo: 80 mg/kg (2-5D preg) [Endocrinology (Baltimore). (Williams and Wilkins Co., 428 E. Preston St., Baltimore, MD 21203) V.1- 1917- v. 81, p. 1091, 1967 (ENDOAO)]
The daily oral application of androstendion to rats two weeks prior to mating and 0-20 day of pregnancy results in specific developmental abnormalities of the urogenital system; TDLo: 280 mg/kg (2W pre/0-20D preg) [Food and Chemical Toxicology. (Pergamon Press Inc., Maxwell House, Fairview Park, Elmsford, NY 10523) V.20- 1982- v. 42, p. 917, 2004 (FCTOD7)]
The daily oral adminsitration of androstendione to female rats 14 day pre-mating and until day 19 after conception led to specific developmental abnormalities (central nervous system); TDLo: 1980 mg/kg (14D pre/-19D preg) [Toxicology and Industrial Health. (Princeton Scientific Pub. Co., POB 2155, Princeton, NJ 08540) V.1 -1985- v. 23,p. 65, 2007 (TIHEEC)]
Intramuscular application of androstendione to rats on day 14-21 of pregnancy results in specific developmental abnormalities on skin and skin appendages as well as effects on newborn: Live birth index (similar to fetuses per litter, except measured after birth) and delayed effects; TDLo: 80 mg/kg (14-21D preg) [Journal of Comparative and Physiological Psychology. (Washington, DC) V.40-96, 1947-82. v. 92, p. 13, 1978 (JCPPAV)]
Intramuscular administration of androstendione to rats on day 14-21 day of pregnancy leads to specific developmental abnormalities of the urogenital system and effects on newborn (e.g., reduced weight gain); TDLo: 40 mg/kg (14-21D preg [Journal of Comparative and Physiological Psychology. (Washington, DC) V.40-96, 1947-82. v. 92, p. 13, 1978 (JCPPAV)]
Androstendione administered subcutaneously to rats on day 5 of pregnancy results in pre-implantation mortality (e.g., reduction in number of implants per female; total number of implants per corpora lutea); TDLo: 20 mg/kg (5D preg) [Journal of Endocrinology. (Biochemical Soc. Book Depot, POB 32, Commerce Way, Colchester, Essex CO2 8HP, UK) V.1- 1939- v. 18, p. 271, 1959 (JOENAK)]
Subcutaneous application of androstendione to rats on day 8 of pregnancy results in post-implantation mortality (e.g., dead and/or resorbed implants per total number of implants); TDLo: 20 mg/kg (8D preg) [Journal of Endocrinology. (Biochemical Soc. Book Depot, POB 32, Commerce Way, Colchester, Essex CO2 8HP, UK) V.1- 1939- v. 18, p. 271, 1959 (JOENAK)]
Justification for classification or non-classification
For reproductive toxicity classification warranted as Repr. 1A (H360F/D: May damage fertility or the unborn child) according to Regulation (EC) 1272/2008. Additionally, classification is warranted for effects on or via lactation H362 according to Regulation (EC) 1272/2008 (May cause harm to breast-fed children).
The classification is in accordance with German legislation for classification of androgenic steroids. The German Committee on Hazardous Substances (AGS) recommended for androgenic steroids classification as Repr. Cat. 1 for effects on fertility and Repr. Cat. 2 for developmental toxicity (each according to criteria of Directive 67/458/EEC). (See argumentation for the assessment of steroid hormones, Technical Rule for Hazardous Substances 905; elaborated by the German Committee on Hazardous Substances (AGS) and published by the German Federal Ministry of Labour and Social Affairs, version of 2008/2005/1999, only available in German, http://www.baua.de/de/Themen-von-A-Z/Gefahrstoffe/TRGS/Begruendungen-905-906.html).
Additional information
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