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Toxicological information

Toxicity to reproduction

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Administrative data

Endpoint:
screening for reproductive / developmental toxicity
Remarks:
based on test type (migrated information)
Type of information:
migrated information: read-across from supporting substance (structural analogue or surrogate)
Adequacy of study:
key study
Reliability:
1 (reliable without restriction)
Rationale for reliability incl. deficiencies:
other: GLP compliant study conducted in accordance with internationally recognised test methods
Cross-referenceopen allclose all
Reason / purpose:
reference to same study
Reason / purpose:
reference to other study

Data source

Referenceopen allclose all

Reference Type:
study report
Title:
Unnamed
Year:
1997
Report Date:
1997
Reference Type:
publication
Title:
Unnamed
Year:
1997
Report Date:
1997

Materials and methods

Test guideline
Qualifier:
according to
Guideline:
OECD Guideline 422 (Combined Repeated Dose Toxicity Study with the Reproduction / Developmental Toxicity Screening Test)
Deviations:
no
Principles of method if other than guideline:
not applicable
GLP compliance:
yes (incl. certificate)
Limit test:
no

Test material

Reference
Name:
Unnamed
Type:
Constituent
Details on test material:
- Name of test material (as cited in study report): tetrahydromethyl-1,3-isobenzofurandione
- Analytical purity: 99.7%
- Lot/batch No.: 2522
- Stability under test conditions: stable, Vehicle: Corn oil (nakaraitesk, lot No, V5P5523)
- Storage condition of test material: room temperature, dark place
- Molecular formula (if other than submission substance): C9 H10 O3
- Molecular weight (if other than submission substance): 166.18
- Smiles notation (if other than submission substance): O=C(OC(=O)C1CC=C(C2)C)C12
- InChl (if other than submission substance): 1/C9H10O3/c1-5-2-3-6-7(4-5)9(11)12-8(6)10/h2,6-7H,3-4H2,1H3
- Structural formula attached as image file (if other than submission substance): see Fig. (11070-44-3 structure.jpg)

Test animals

Species:
rat
Strain:
Crj: CD(SD)
Sex:
male/female
Details on test animals and environmental conditions:
TEST ANIMALS
- Source: Charles river Japan
- Age at study initiation: purchase at 9 weeks old, 1st. administration at 10 weeks old
- Weight at study initiation: male: 356.3-394.4g, female: 213.5-252.9g
- Fasting period before study: 18hr
- Housing: dosing period: stainless hanger gage, one animal/gage, mating period: polycarbonate gage with wood chip
- Diet (e.g. ad libitum): ad libitum
- Water (e.g. ad libitum): ad libitum
- Acclimation period: one week


ENVIRONMENTAL CONDITIONS
- Temperature (°C): 22-26°C
- Humidity (%): 45-65%
- Air changes (per hr): 13 times/hr
- Photoperiod (hrs dark / hrs light):12/12 AM07:00-PM07:00

Administration / exposure

Route of administration:
oral: gavage
Type of inhalation exposure (if applicable):
not specified
Vehicle:
corn oil
Details on exposure:
VEHICLE
- Justification for use and choice of vehicle (if other than water): Corn oil is used generally
- Concentration in vehicle: 0.6, 2 and 6w/v%
- Amount of vehicle (if gavage): 5mL/kg
- Lot/batch no. (if required): V5P5831, nakalai tesque Co.
Details on mating procedure:
Male/female per cage: 1/1,
length of cohabitation: maximal 14 days, until proof of pregnancy (formation of vaginal closing or sperm detection in vagina)
Analytical verification of doses or concentrations:
not specified
Details on analytical verification of doses or concentrations:
no details given
Duration of treatment / exposure:
Males; for 49 days Females; from 14 days before mating to day 3 of lactation (38 days in total)
Frequency of treatment:
one administration/day
Details on study schedule:
no details given
Doses / concentrations
Remarks:
Doses / Concentrations:
0 (Vehicle), 30, 100 and 300 mg/kg/day (in corn oil)
Basis:
nominal conc.
No. of animals per sex per dose:
Doses is 0, 30, 100 and 300 mg/kg. 12 animals per sex per dose.
Control animals:
yes, concurrent vehicle
Details on study design:
Dose selection rationale: oral, one of the identical exposure route for human
300 mg/kg: 1/3 volume from omens of death (1000 mg/kg)
100 and 30 mg/kg: common ratio 3 of 300 mg/kg
Positive control:
no details given

Examinations

Parental animals: Observations and examinations:
CAGE SIDE OBSERVATIONS: Yes
- Time schedule: one time per day
- Cage side observations: general symptom

DETAILED CLINICAL OBSERVATIONS: No
BODY WEIGHT: Yes
- Time schedule for examinations: male: two times/week
female: two times/ week at pre-mating period, in pregnant period: day at 0, 4, 7,10, 14, 17 and 21, in lactation period: the day 0 and 4.

FOOD CONSUMPTION AND COMPOUND INTAKE:
- Food consumption for each animal determined and mean daily diet consumption calculated as g food/kg body weight/day: Yes
male: two times/week
female: two times/ week at pre-mating period, in pregnant period: day at 1, 4, 7,10, 14, 17 and 21, in lactation period: the day 1 and 4.

FOOD EFFICIENCY:
- Body weight gain in kg/food consumption in kg per unit time X 100 calculated as time-weighted averages from the consumption and body weight gain data: No

OPHTHALMOSCOPIC EXAMINATION: No

HAEMATOLOGY: Yes
- Time schedule for collection of blood: after dosing period
- Anaesthetic used for blood collection: Yes (identity): Pentobarbital-Na i.p.
- Animals fasted: Yes
- How many animals: All of male
- Parameters checked in table (see below in remarks field) were examined.: WBC, RBC, Hb, Ht, PLT

CLINICAL CHEMISTRY: Yes
- Time schedule for collection of blood: after dosing period (same time for HEMATOLOGY)
- Animals fasted: Yes
- How many animals:All of male
- Parameters checked in table (see below in remarks field) were examined.: TP, ALB, A/G, Bil, GOT, GPT, TGace, ALP, TG, PL, Giu, BUN, CRE, P, Ca, Na, K, Cl

URINALYSIS: No

NEUROBEHAVIOURAL EXAMINATION: No
Oestrous cyclicity (parental animals):
no details given
Sperm parameters (parental animals):
no details given
Litter observations:
Body weight (at day of birth and day 4 after birth), sex, surface abnormality at day of birth.
Postmortem examinations (parental animals):
SACRIFICE
- Male animals: All surviving animals, as soon as possible after the last litters in each generation were produced.
- Maternal animals: All surviving animals, after the last litter of each generation was weaned.

GROSS NECROPSY
- Gross necropsy consisted of external and internal examinations including the cervical, thoracic, and abdominal viscera.
organ weight: brain, heart, lung, thymus, liver, spleen, kidney, adrenal, testis, epididymis, ovary.
microscopic investigation: all animals in control, 300 mg/kg group; brain, pituitary gland, eyeball, thyroid gland, parathyroid gland, thymus, heart, lung, liver, kidney, adrenal, spleen, stomach, small intestine, large intestine, pancreas, urinary bladder, bone marrow, ovary, uterus, vagina, mammary gland.
Unfertilized animals in any groups: testes, epididymis and ovary
Postmortem examinations (offspring):
Full macroscopic examinations on all of pups Parameters assessed during study.
Statistics:
bartlett method,
standard variance: Dunnett, multiple comparison
non-standard variance: Steel, multiple comparison
Reproductive indices:
No. of pairs with successful copulation
Copulation index (No. of pairs with successful copulation/No. of pairs mated x 100)
Pairing days until copulation
No. of pregnant females
Fertility index = (No. of pregnant animals x 100/No. of pairs with successful copulation),
No. of corpora lutea
No. of implantation sites
No. of living pregnant females
No. of pregnant females with parturition gestation length
No. of pregnant females with live pups on day 0
Gestation index (No. of females with live pups x 100/No. of living pregnant females)
Delivery index (No. of pups born x 100/No. of implantation sites)
Offspring viability indices:
No. of pups alive on day 0 of lactation
Live birth index (No. of live pups on day 0 x 100/No. of pups born)
Sex ratio (Total No. of male pups/Total No. of female pups)
No. of pups alive on day 4 of lactation, body wt. of live pups (on day 0 and 4)

Results and discussion

Results: P0 (first parental animals)

General toxicity (P0)

Clinical signs:
no effects observed
Body weight and weight changes:
no effects observed
Food consumption and compound intake (if feeding study):
no effects observed
Organ weight findings including organ / body weight ratios:
no effects observed
Gross pathological findings:
no effects observed
Histopathological findings: non-neoplastic:
no effects observed
Other effects:
no effects observed

Reproductive function / performance (P0)

Reproductive function: oestrous cycle:
no effects observed
Reproductive function: sperm measures:
not examined
Reproductive performance:
no effects observed

Details on results (P0)

For details on results for parental animals, please refer to IUCLID5 section 7.5.1 (repeated dose toxicity oral).
Reproduction parameters:
- At 30 and 100 mg/kg, there was a tendency for decrease of estrous frequency, but at 300 mg/kg, no statistically significant effects were observed.
- For details see tables below.

Effect levels (P0)

Dose descriptor:
NOAEL
Effect level:
300 mg/kg bw/day (nominal)
Sex:
male/female
Basis for effect level:
other: no effects were observed

Results: F1 generation

General toxicity (F1)

Clinical signs:
no effects observed
Mortality / viability:
no mortality observed
Body weight and weight changes:
no effects observed
Sexual maturation:
not examined
Organ weight findings including organ / body weight ratios:
not examined
Gross pathological findings:
no effects observed
Histopathological findings:
not examined

Details on results (F1)

No adverse effects were reported.
- At 30 and 100 mg/kg, statistically significant decrease of birth index was observed, and at 300 mg/kg, stillborn was observed only one animal (not statistically significant).
- At 100 mg/kg, total litter loss in two dams were observed.
- At 300 mg/kg, no statistically significant effects were observed, but there was a tendency for decrease of developmental parameters (total number of pups born, delivery index and live birth index).
- For details see table below.

Effect levels (F1)

Dose descriptor:
NOAEL
Generation:
F1
Effect level:
300 mg/kg bw/day (nominal)
Sex:
male/female
Basis for effect level:
other: no effects were observed

Overall reproductive toxicity

Reproductive effects observed:
not specified

Any other information on results incl. tables

Table 1: Reproduction parameters

Dose level (mg/kg/day)

0

30

100

300

No. of dams

11

11

11

10

No. of corpora lutea

(Mean +/- SD)

22.18 +/-0.40

22.27 +/-0.47

22.09 +/-0.30

22.30
 +/-0.48

No. of implantations

(Mean +/- SD)

183

16.64 +/- 1.63

188

17.09 +/- 1.30

188

17.09 +/- 0.94

162

16.20 +/- 1.03

No. of litter

(Mean +/- SD)

171

15.55 +/- 2.58

178

16.18 +/- 1.25

181

16.45 +/- 0.69

154

15.40 +/- 1.65

Gestation Index

100

100

100

100

No. of stillborns

Male

Female

Total

%

 

0

0

0

(0)

 

4

4

8

(5.06)*

 

3

6

9

(5.33)*

 

4

6

10

(6.76)

No. of live newborns

(Mean +/- SD)

162

14.73 +/- 2.65

150

13.64 +/- 1.43

160

14.55 +/- 0.82

138

13.80 +/- 2.53

Birth index

94.74

84.27*

88.40*

89.61

Sex ratio of live newborns (male/female)

80/82

71/79

83/77

64/74

Body weight of live pups (g) (mean +/- SD) on day 0

Males

Females

 

 

6.2 +/- 0.5

9.4 +/- 1.2

 

 

6.1 +/- 0.4

9.5 +/- 1.1

 

 

6.0 +/- 0.4

9.1 +/- 0.7

 

 

6.3 +/- 0.5

9.9 +/- 0.9

Body weight of live pups (g) (mean +/- SD) on day 4

Males

Females

 

 

6.0 +/- 0.4

9.0 +/- 1.3

 

 

5.9 +/- 0.4

9.2 +/- 1.1

 

 

5.8 +/- 0.3

8.8 +/- 0.5

 

 

6.0 +/- 0.5

9.5 +/- 1.0

Viability index

98.15

94.00

81.88

93.48

No. of external anomalies

0

0

0

0

Gestation index = (Number of dams with live newborns/Number of pregnant females) x 100

Birth index = (Number of newborns/Number of implantations) x 100

Viability index = (Number of live newborns on day 4 after birth/Number of live newborns) x 100

*: P<0.05 significantly different from control

Background level of stillborn : 0-14.84%

Background level of birth index : 80.98-96.61%

Applicant's summary and conclusion

Conclusions:
The NOAEL is considered to be 300 mg/kg/day for reproductive performance of parents and for development of offspring.
Executive summary:

In a combined repeated dose toxicity/reproduction and developmental toxicity study tetrahydromethylphthalic anhydride (MTHPA), of which 3 -MTHPA D4 is an isomer, was administered to groups of Crj:CD(SD) rats (12/sex), via gavage in corn oil at dose levels of 0 (Vehicle), 30, 100 and 300 mg/kg bw/day.

No effects on the oestrous cycle, numbers of corpora lutea and implantations, copulation index or fertility indices were observed to indicate an effect on reproductiver performance. Examination at delivery and during the lactation period revealed, no effects related to the test article in terms of gestational days, litter size and live newborns, gestation index, stillborn index, birth index, sex ratio, body weights of offspring at birth and at day 4 after birth, or viability index on day 4. No external anomalies were apparent. The NOAEL was considered to be 300mg/kg/day for reproductive performance of parents and for development of offspring.