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Toxicological information

Developmental toxicity / teratogenicity

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Administrative data

Endpoint:
developmental toxicity
Type of information:
experimental study
Adequacy of study:
key study
Reliability:
1 (reliable without restriction)
Rationale for reliability incl. deficiencies:
other: Well conducted study, carried out by Nippon Bioresearch Inc.Hashima Laboratory (Japan).

Data source

Reference
Reference Type:
publication
Title:
Unnamed
Year:
1997

Materials and methods

Test guideline
Qualifier:
according to
Guideline:
other: OECD testing guideline 422
Deviations:
yes
Remarks:
, older version of method that did not contain the functional observational battery
GLP compliance:
yes
Limit test:
no

Test material

Reference
Name:
Unnamed
Type:
Constituent

Test animals

Species:
rat
Strain:
Crj: CD(SD)
Details on test animals and environmental conditions:
TEST ANIMALS
- Source: Charles River Japan
- Age at study initiation: 10 weeks
- Weight at study initiation: male 341~380 g; the female was 232~256 g.
- Housing: suspended, stainless steel cage; 5/cage until breeding, then divided into separate rearing cages.
- Diet (e.g. ad libitum): ad libitum
- Water (e.g. ad libitum): ad libitum
- Acclimation period: 5 day quarantine; 7 day acclimation

ENVIRONMENTAL CONDITIONS
- Temperature (°C): 20 ~ 24 ℃
- Humidity (%): 40 to 70%
- Photoperiod (hrs dark / hrs light): 12 hour light / 12 hour dark

Administration / exposure

Route of administration:
oral: gavage
Vehicle:
water
Details on exposure:
PREPARATION OF DOSING SOLUTIONS: dissolved in water
Analytical verification of doses or concentrations:
not specified
Details on mating procedure:
- M/F ratio per cage: 1/1
- Length of cohabitation: 14 days
- Proof of pregnancy: sperm in vaginal smear referred to as day 0 of pregnancy
- After successful mating each pregnant female was caged (how): separate rearing cages
Duration of treatment / exposure:
Males, 49 days; Females, from 14 days before mating to day 3 of lactation
Frequency of treatment:
Once daily
Duration of test:
Male, 50 days; Females, day 4 of lactation
No. of animals per sex per dose:
12
Control animals:
yes, concurrent vehicle
Details on study design:
Sex: male/female
Post-exposure period: Male, 50 days; Females, day 4 of lactation
- Dose selection rationale: based on range-finding
- Rationale for animal assignment (if not random): random

Examinations

Maternal examinations:
CAGE SIDE OBSERVATIONS: Yes
- Time schedule: twice daily
- Cage side observations checked : general condition and mortality; estrus and abnormal labor conditions in females

BODY WEIGHT: Yes
- Time schedule for examinations: twice per week in males; before mating, twice a week during the mating period, 0, 7 ,14 and 21 days duirng pregnancy, during the feeding period was measured 0 and 4 days in females

FOOD CONSUMPTION AND COMPOUND INTAKE (if feeding study): one week prior to mating, then twice a week; additionally, in females, days 2,9,16 and 21 of pregnancy, four days over the feeding period.
- Food consumption for each animal determined and mean daily diet consumption calculated as g food/kg body weight/day: No data
- Compound intake calculated as time-weighted averages from the consumption and body weight gain data: No data

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

WATER CONSUMPTION AND COMPOUND INTAKE (if drinking water study): No

OPHTHALMOSCOPIC EXAMINATION: No

HAEMATOLOGY: Yes
- Time schedule for collection of blood: day after treatment
- Anaesthetic used for blood collection: Yes; sodium pentobarbital
- Animals fasted: No data
- How many animals: No data
- Parameters checked in table [No.1] were examined.

CLINICAL CHEMISTRY: Yes
- Time schedule for collection of blood: day after treatment
- Animals fasted: No data
- How many animals: No data
- Parameters checked in table [No.2] were examined.

URINALYSIS: No

Estrous cyclicity (Parental animals)
Once daily from the dosing start date until successful mating was observed.

Sperm parameters (Parental animals)
Parameters examined in P male parental generations:
testis weight, epididymis weight
Fetal examinations:
STANDARDISATION OF LITTERS
- Performed on day 4 postpartum: yes

PARAMETERS EXAMINED
The following parameters were examined in F1 offspring:
number and sex of pups, stillbirths, live births, postnatal mortality, presence of gross anomalies, weight gain

GROSS EXAMINATION OF DEAD PUPS:
yes, for external and internal abnormalities; possible cause of death was not determined for pups born or found dead

Statistics:
Newborn screening as a unit has an average of one litter.
Weight (the parent animals, babies), food consumption, number of estrus, days mating, pregnancy [Day delivery (feeding 0) - date confirmed mating, the number of implantation scars, the number of birth control mobilize (number of babies stillborn baby + ), the number of newborn, number of children born dead, birth rate [(number of birth control mobilize / number of implantation scars) × 100], rate of production of child [(number of infant feeding 0 days / number of implantation scars) × 100], corpus number, implantation rates [(number of implantation scars / number of corpora lutea) × 100], fertility [(number of infant feeding 0 day / mobilize all of birth control) × 100], feeding baby number four day, feeding 4 day survival rate [(number of infant feeding 4 days / 0 Number of infant feeding day) × 100], unusual occurrence rate [(number of children with abnormal/ number of newborns) × 100], sex ratio (male / female), organ weights ( including the relative weight), results of blood tests, blood biochemistry test results for the mean and standard deviation were calculated for each group.
Significant difference test, Bartlett's test and the homoscedasticity of Law, analysis of variance, Dunnett method. Kruskal-Wallis test.
Copulation rate [(number of established animal mating / number of live animals) × 100], fertility [(number of female fertility / Establishment of animal mating) × 100], the birth rate [(number of female newborns / number of female fertility) × 100] is, χ ^ 2 using the test.
Cochran • Armitage was carried out using a test of dose-response trend test.
Indices:
Reproductive indices
Copulation rate [(number of established animal mating / number of live animals) × 100], fertility [(number of female fertility / Establishment of animal mating) × 100], pregnancy [Day delivery (feeding 0) - date confirmed mating, birth rate [(number of birth control mobilize / number of implantation scars) × 100], rate of production of child [(number of infant feeding 0 days / number of implantation scars) × 100], implantation rates [(number of implantation scars / number of corpora lutea) × 100], fertility [(number of infant feeding 0 day / mobilize all of birth control) × 100]

Offspring viability indices
the birth rate [(number of female newborns / number of female fertility) × 100], unusual occurrence rate [(number of children with abnormal/ number of newborns) × 100], feeding 4 day survival rate [(number of infant feeding 4 days / 0 Number of infant feeding day) × 100]

Results and discussion

Results: maternal animals

Maternal developmental toxicity

Details on maternal toxic effects:
Maternal toxic effects:yes

Details on maternal toxic effects:
:[Males]
1) General condition: With the survival animals, no death and no moribund were found for 30, 100 and 300 mg/kg/day groups. At 1000 mg/kg/day, one death on day 20 of dosing was seen and abnormality wasn't seen except for salivation until the previous day. With the dead animals, no abnormality was found for 30, 100 and 300 mg/kg/day groups. At 1000 mg/kg/day, salivation was seen in about 1 to 30-minutes after dosing from day 3. 2) Body weight: No significant difference from control group was seen in 30, 100, and 300 mg/kg/day groups. At 1000 mg/kg/day, the significant low value was recorded during day 18 to day 25 of dosing andduring day 32 to day 50 of dosing.
3) Food consumption: At 30 and 300 mg/kg/day, no significant difference from control was seen. At 100 mg/kg/day, the significant high values were seen on day 31. but no dose-related changes were obserbed.At 1000 mg/kg/day, the statistically significant low values were recorded on day 13, 31 and during day 38 to day 45.
4) Hematological examination: No significant difference from control group was seen for all groups up to 1000 mg/kg/day dose.
5) Blood chemical examination: At 30 and 300 mg/kg/day,the significant high value in BUN were seen. As the difference was very small, this was not considered as the adverse effect of HEMA dosing. At 100 mg/kg/day, a higher value of BUN but not statistically signifficant difference from control was recorded. At 1000 mg/kg/day, the significant high values were recorded in BUN, K, Cl,I-phosphorous and Triglyceride.
6) Autopsy: No abnormalitywas found for 30 and 100 mg/kg groups. In the 300 mg/kg group, the albedo spot in the kidney of the unilateral in the 1 animal and, the atrophy of the testiculus of the bilaterality and softening were observed in the 1 animal. In the 1000 mg/kg group, the dark-red of the thymus gland in the 1 animal and the hypertrophy of the kidney of bilaterality in the 1 animal were observed.
7) Weight oforgans: At 30 mg/kg/day, no significant difference from control group in absolute and relative weight was seen for all organs. At 100 and 300 mg/kg/day, the significant high value was recorded in the absolute weight of kidneys. At 1000 mg/kg/day, the statistically significant high values were recorded in the relative weight of liver and kidneys.
8) Histopathological examination: At 1000 mg/kg/day in the survival animals, the dilatation of renal tubule in 3 animals in the kidney and the dilatation of collecting tubules in 2 animals were obserbed. But, all these changes were just slight. And the dilatation of renal tubule has a significant difference but no dose-related changes. As for the dilatation of collecting tubules, it has no significant difference but increase tendency. In the other group, there were hemorrhage of thymus gland, microgranuloma of the heart, microgranuloma of the liver and hepatocyte vacuolar degeneration of the centrilobular, renal basophilic tubules, eosinophilic corpuscle in proximal tubule, cyst, diffusive mineral deposition and neutrophilic infiltration. But it was judged with the incidental change, because they were whether it equivalently seems even in the control group or small number animals. And no abnormality was observed in spleen, adrenal, testiculus and brain in the control and 1000 mg/kg group. In animal of death of the 1000 mg/kg group, there were hemorrhage of the thymus gland, edema of the lung, autolysis of adrenal and lung and thymus gland with the deadanimal of 1000 mg/kg group. As for those degrees, all were just slight. In the adrenal with the abnormality in the autopsy, no change which suggested hypertrophy was seen.
[Females]
1) General condition: With the existence animales, no death and no moribund were seen for 30, 100 and 300 mg/kg/day groups. At 1000 mg/kg/day, three death on day 6 of dosing, one death on day 12 of dosing and one death on day 17 of dosing were seen. Salivation, decrease in locomotor activity, adoption of a prone position, acrimation, soiled fur, hypothermia, bradypnea were seen at 1000 mg/kg. With the death animals, no abnormality was found for 30, 100 and300 mg/kg/day groups. At 1000 mg/kg/day, salivation was seen in about 1 to 30-minutes after dosing from day 3.
2) Body weight: Before mating period, no significant difference from control group was seen at 30, 100 and 300 mg/kg/day. At 1000 mg/kg/day, the significant lower values were recorded on day 4 and 5 of dosing. During gestation period, no significant difference from control groups was seen in 30, 300 and 1000 mg/kg/day groups. At 100 mg/kg/day, the significant high values were recorded on day 21 of gestation, but no dose-related changes were observed. During lactation period, no significant difference from control groups was seen in 300 and 1000 mg/kg/day groups. At 30 and 100 mg/kg/day, the significant high values were recorded on day 4 of lactation, but no dose-related changes were obserbed.
3) Food consumption: Before mating period, no significant difference from control group was seen at 30, 100 and 300 mg/kg/day. At 1000 mg/kg/day, the significant low value from control group was recorded on day 3, 6 and 13 of dosing. During gestation period, no significant difference from control groups was seen in 30 and 300 mg/kg/day groups. At 100 and 1000 mg/kg/day, the significant high value from control group was recorded on day 16 of gestation, but no dose-related changes were observed. During lactation period, no significant difference from control groups was seen.
4) Weight of organs: At 30 mg/kg/day, no significant difference from control group in absolute and relative weight was seen for all organs. At 100 mg/kg/day,the significant high value was recorded in the absolute weight of kidneys. At 1000 mg/kg/day, the significant high values were recorded in the relative and absolute weight of kidneys.
5) Histopathological examination: Though at 1000 mg/kg/day survival groups, neutrophilic infiltration (unilateral ) to medulla and papilla mammae part in the kidney were observed in the 1 animal, the degree was slight. Though extensive softening of the medulla oblongata in the brain was observed in the 1 example at 1000 mg/kg group, the degree was slight. In dead 6 animals of the 1000 mg/kg group, there were the edema in 1 animal in the lung, the atrophy in 1 animal in the thymus gland, the atrophy in 5 animals and the atrophy of a Malpighian body in 1 animals in the spleen, the hyperplasia of zona fasciculata in 3 animals and the autolysis in 1 animal in the the adrenal and the erosion in 1 animal in the small intestinal mucosa. The degrees of the atrophy in the thymus gland and the atrophy of a Malpighian body were moderate, but the others were slight. All the changes are noted related agonism. No changes which suggested, though the hypertrophy of the adrenal in 2 animals, dark-red of the glandular stomach mucosa in 2 animals and dark-red of the intestinum tenue were observed as abnormal in the autopsy of the 1000 mg/kg group.

There were no effects of the test substance on the estrus frequency, copulation index, number of conceiving days, fertility index, length of gestation, number of corpora lutea or gestation index.

Effect levels (maternal animals)

Dose descriptor:
NOAEL
Effect level:
>= 1 000 mg/kg bw/day
Basis for effect level:
other: maternal toxicity

Results (fetuses)

Details on embryotoxic / teratogenic effects:
Embryotoxic / teratogenic effects:no effects

Details on embryotoxic / teratogenic effects:
There were no effects of the test substance on the number of live pups born, birth index, number of dead pups, number of pups born, delivery index, live birth index, sex ratio, viability index, external anomalies, body weight or necropsy findings.

Effect levels (fetuses)

Dose descriptor:
NOAEL
Effect level:
>= 1 000 mg/kg bw/day
Basis for effect level:
other: teratogenicity

Fetal abnormalities

Abnormalities:
not specified

Overall developmental toxicity

Developmental effects observed:
not specified

Applicant's summary and conclusion

Conclusions:
An OECD 422 study was conducted with rats by gavage at doses of 0, 30, 100, 300 and 1000 mg/kg. The NOAEL for maternal toxicity and teratogenicity and is considered to be greater than 1000 mg/kg.

Executive summary:

2-Hydroxyethyl methacrylate was studied for oral toxicity in rats in an OECD combined repeat dose and reproductive/developmental toxicity screening test at doses of 0, 30, 100, 300 and 1000 mg/kg/day.

There were no effects of the test substance on the estrus frequency, copulation index, number of conceiving days, fertility index, length of gestation, number of corpora lutea or gestation index.

There were no effects of the test substance on the number of live pups born, birth index, number of dead pups, number of pups born, delivery index, live birth index, sex ratio, viability index, external anomalies, body weight or necropsy findings.

Therefore, the NOAELs for maternal toxicity and teratogenicity are considered to be >/=1000 mg/kg/day for reproductin in both males and females and as well as for development of pups.