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Toxicological information

Repeated dose toxicity: oral

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Administrative data

Endpoint:
sub-chronic toxicity: oral
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:
OECD Guideline 422 (Combined Repeated Dose Toxicity Study with the Reproduction / Developmental Toxicity Screening Test)
Deviations:
yes
Remarks:
, An old version of OECD 422 (not containing functional observation battery test) had been  conducted.
GLP compliance:
yes
Limit test:
no

Test material

Reference
Name:
Unnamed
Type:
Constituent

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: 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 oral exposure:
PREPARATION OF DOSING SOLUTIONS: dissolved in water


VEHICLE
- Justification for use and choice of vehicle (if other than water): water
- Concentration in vehicle: 5 mL/kg
Analytical verification of doses or concentrations:
not specified
Duration of treatment / exposure:
Males, 49 days; Females, from 14 days before mating to day 3 of lactation
Frequency of treatment:
Once daily
Doses / concentrations
Remarks:
Doses / Concentrations:
0 (vehicle), 30, 100, 300, 1000 mg/kg/day
Basis:

No. of animals per sex per dose:
12
Control animals:
yes
Details on study design:
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
Positive control:
not applicable

Examinations

Observations and examinations performed and frequency:
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


NEUROBEHAVIOURAL EXAMINATION: No
Sacrifice and pathology:
Terminal kill: Males, day 50; Females, day 4 of lactation
GROSS PATHOLOGY: Yes; Thymus, liver, kidney, testis and epididymis weight in males and ovary in females was measured after removal, adrenal gland, brain, heart and spleen and 10% neutral buffered formalin solution (However, testicular and epididymal fluid Buan) was fixed. Post-mortem examination of feamles who did not give birth to Day 25 of pregnancy. Number of corpora lutea and the number of implantation scars in females.

HISTOPATHOLOGY: Yes; Paraffin-embedded specimens were prepared. Control group and 1000 mg / kg group of heart, liver, spleen, thymus, kidney, testis and epididymis in males ovary in females, adrenal and brain for the Preparation HE staining of tissue was examined histologically. In males, 1000 mg / kg in the kidney was considered to indicate a difference in the number of abnormal animals in the test group compared with the control group; 30, 100 and 300 mg / kg group were similarly examined. In females, 1000 mg / kg differences in the brain was considered to indicate an abnormal number of animals in the test group than the control group and changes in adrenal cases and 30, 100, 300 mg / kg group were similarly examined.
Other examinations:
Fetal examinations
(1) number of preterm birth and sex, number of stillborn children, the presence of abnormalities observed and the number of newborn.
(2) general condition and mortality
(3) measurement of body weight
(4) autopsy
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.

Results and discussion

Results of examinations

Clinical signs:
effects observed, treatment-related
Mortality:
mortality observed, treatment-related
Body weight and weight changes:
effects observed, treatment-related
Food consumption and compound intake (if feeding study):
effects observed, treatment-related
Food efficiency:
not examined
Water consumption and compound intake (if drinking water study):
not examined
Ophthalmological findings:
not examined
Haematological findings:
effects observed, treatment-related
Clinical biochemistry findings:
effects observed, treatment-related
Urinalysis findings:
not examined
Behaviour (functional findings):
not examined
Organ weight findings including organ / body weight ratios:
effects observed, treatment-related
Gross pathological findings:
effects observed, treatment-related
Histopathological findings: non-neoplastic:
effects observed, treatment-related
Histopathological findings: neoplastic:
no effects observed
Details on results:
Detail:[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.

Effect levels

open allclose all
Dose descriptor:
NOAEL
Effect level:
100 mg/kg bw/day (nominal)
Based on:
test mat.
Sex:
male
Basis for effect level:
clinical biochemistry
organ weights and organ / body weight ratios
Dose descriptor:
NOAEL
Effect level:
300 mg/kg bw/day (nominal)
Based on:
test mat.
Sex:
female
Basis for effect level:
organ weights and organ / body weight ratios
histopathology: non-neoplastic

Target system / organ toxicity

Critical 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 NOELs for repeat dose toxicity are considered to be less than 30 mg/kg for males, and 30 mg/kg for females.
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. One male and 6 females of the 1000 mg/kg group (12 animals of each sex) died during the treatment period. In the males, BUN was elevated or tended to be high at 30 mg/kg or more, and the relative kidney weights were increased at 100 mg/kg or more. Salivation, suppression of body weight gain, decrease in food consumption, iucreased K, C1 and inorganic phosphorous, decreased triglyceride, increased relative liver weights, dilatation of renal tubules and collection tubules in the kidney were seen at 1000 mg/kg. In the females, the relative kidney weights were elevated or tended to be high at 100 mg/kg or more. Salivation, decrease in locomotor activity, adoption of a prone position, lacrimation, soiled fur, hypothermia, bradypnea, suppression in body weight gain, decrease in food consumption, increases of absolute and relative kidney weights, neutrophil cellular infiltration in the papilla and medulla and massive malacia in the medulla oblongata were seen at 1000 mg/kg. The NOELs for repeat dose toxicity are considered to be less than 30 mg/kg for males, and 30 mg/kg for females.