Registration Dossier

Administrative data

Endpoint:
two-generation reproductive toxicity
Remarks:
based on test type (migrated information)
Type of information:
experimental study
Adequacy of study:
key study
Reliability:
1 (reliable without restriction)
Rationale for reliability incl. deficiencies:
other: Comparable to guideline study. Reliability was adopted from OECD SIDS Draft.

Data source

Referenceopen allclose all

Reference Type:
publication
Title:
Teratology and multigeneration reproduction studies with maleic anhydride in rats
Author:
Short, R. D., Johannsen, F. R., Levinskas, G. J., Rodwell, D. E., and Schardein, J. L.
Year:
1986
Bibliographic source:
Fundam. Appl. Toxicol. 7: 359-366
Reference Type:
publication
Title:
Unnamed
Year:
1982
Report Date:
1982
Reference Type:
publication
Title:
Unnamed
Year:
1991
Report Date:
1991
Reference Type:
secondary source
Title:
Unnamed
Year:
1982
Reference Type:
secondary source
Title:
Teratology and multigeneration reproduction studies with maleic anhydride in rats
Author:
Short, R. D., Johannsen, F. R., Levinskas, G. J., Rodwell, D. E., and Schardein, J. L.
Year:
1986
Bibliographic source:
Fundam. Appl. Toxicol. 7: 359-366; cited in OECD SIDS Draft for CAS. Nos. 108-31-8/ 110-16-7, 2005
Reference Type:
secondary source
Title:
A 6-month multispecies inhalation study with maleic anhydride
Author:
Short, R.D., Johannsen, F.R., Ulrich, C.
Year:
1988
Bibliographic source:
Appl. Toxicol. 10: 517-524; cited in OECD SIDS Draft for CAS. Nos. 108-31-8/ 110-16-7, 2005
Reference Type:
publication
Title:
Three Generation Reproduction Study in Rats (Modified to a Two Generation Study)
Author:
Jessup. D.C., Aldrige, D., Schardein, J.L. and Blair, M.
Year:
1982
Bibliographic source:
cited in: EPA, Health and environmental effects profile for maleic anhydride, 06/1986

Materials and methods

Test guideline
Qualifier:
equivalent or similar to
Guideline:
OECD Guideline 416 (Two-Generation Reproduction Toxicity Study)
Deviations:
yes
Remarks:
(proportion Male/female during mating 1/2; oestrus cycle and sperm parameters not analyzed)
GLP compliance:
yes
Limit test:
no

Test material

Reference
Name:
Unnamed
Type:
Constituent
Details on test material:
- Name of test material (as cited in study report): Maleic anhydride
- Analytical purity: > 99%

Test animals

Species:
rat
Strain:
other: Charles River CD rats
Sex:
male/female
Details on test animals and environmental conditions:
TEST ANIMALS
- Age at study initiation: -P/F0: 5-6 wks; -F1: 22 days
- Housing: single (besides mating and lactation period)
- Diet: ad libitum
- Water: ad libitum
- Acclimation period: 16 days


ENVIRONMENTAL CONDITIONS
- Temperature (°C): 21-23
- Humidity (%): 25-60
- Photoperiod (hrs dark / hrs light): 12/12

Administration / exposure

Route of administration:
oral: gavage
Vehicle:
corn oil
Details on exposure:
volume of 10 ml/kg
Details on mating procedure:
- M/F ratio per cage: 1/2
- Length of cohabitation: maximum of 15 days
- Proof of pregnancy: vaginal plug in vaginal smear referred to as day 0 of pregnancy
- After successful mating each pregnant female was caged: individually
Analytical verification of doses or concentrations:
not specified
Duration of treatment / exposure:
- P/F0: from study initiation to the end of the generation
- F1: at 22 days of age and continued throughout the generation (Premating (Premating exposure period: F0 and F1, a minimum of 80 days) and throughout mating, gestation and lactation)
Frequency of treatment:
daily, 7 days/week
Details on study schedule:
P/F0 rats were bred twice to produce the F1a and F1b litters. At weaning, ten males and 20 females from each dose group of the F1b litters were randomly selected to become parents of the F2a and F2b litters. A minimum of nine additional male and eight additional female pups per group were randomly selected to be used as replacements for animals dying prior to initiation of the generation.
Doses / concentrations
Remarks:
Doses / Concentrations:
0, 20, 55, and 150 mg/kg
Basis:
nominal conc.
No. of animals per sex per dose:
10 males, 20 females
Control animals:
yes, concurrent vehicle

Examinations

Parental animals: Observations and examinations:
DETAILED CLINICAL OBSERVATIONS: Yes
- Time schedule: twice a day


BODY WEIGHT: Yes
- Time schedule for examinations: weekly (additionally, female body weights were measured at intervals during gestation and lactation)


FOOD CONSUMPTION AND COMPOUND INTAKE (if feeding study):
- Food consumption for each animal determined and mean daily diet consumption calculated as g food/kg body weight/day: Yes


OTHER: male and female fertility, mean gestation length
Litter observations:
STANDARDISATION OF LITTERS
- Performed on day 4 postpartum: yes
- If yes, maximum of 10 pups/litter (5/sex/litter as nearly as possible); excess pups were killed and discarded.


PARAMETERS EXAMINED
The following parameters were examined in [P/F0 and F1] offspring: number and sex of pups, stillbirths, live births, postnatal mortality, presence of gross anomalies


GROSS EXAMINATION OF DEAD PUPS:
yes, for external and internal abnormalities (besides organ weights); possible cause of death was determined for pups born or found dead.
Postmortem examinations (parental animals):
SACRIFICE
- all P/F0 parents


GROSS NECROPSY
- Gross necropsy consisted of external and internal examinations.


HISTOPATHOLOGY / ORGAN WEIGHTS
These tissues were prepared for microscopic examination and weighed, respectively: adrenal, colon, heart, ileum, duodenum, kidney, liver, lung, bone marrow (sternum), brain, eye, mesenteric lymph node, mammary gland, pituitary, pancreas, salivary gland, skin, ovary, spleen, stomach, testis (with epididymis), thyroid (with a section of thrachea and esophagus), spinal cord (cervical), urinary bladder, prostate, uterus, all other gross lesions including tissue masses
Postmortem examinations (offspring):
SACRIFICE
- all F1 parents
- The F1 offspring not selected as parental animals and all F2 offspring were sacrificed



GROSS NECROPSY
- Gross necropsy consisted of external and internal examinations including the cervical, thoracic, and abdominal viscera.


HISTOPATHOLOGY / ORGAN WEIGTHS
These tissues were prepared for microscopic examination and weighed, respectively: adrenal, colon, heart, ileum, duodenum, kidney, liver, lung, bone marrow (sternum), brain, eye, mesenteric lymph node, mammary gland, pituitary, pancreas, salivary gland, skin, ovary, spleen, stomach, testis (with epididymis), thyroid (with a section of thrachea and esophagus), spinal cord (cervical), urinary bladder, prostate, uterus, all other gross lesions including tissue masses
Statistics:
All statistical analyses compared the treatment groups with the control group, with a level of significance at p<0 .05. Significance at p<0 .01 was also indicated. 1. Parental Body Weights: The parental body weights by sex were analyzed by one-way analysis of variance, Bartlett's test for homogeneity of variances, and the appropriate t-test (for equal or unequal variances). Significant differences were determined using Dunnett's multiple comparison tables. Analyses for the P/F0 generation were conducted at one week prior to the F1a mating (week 11) and at termination of the generation (week 32). Analyses for the F1 generation were conducted at the first week of the generation (week 30), one week prior to the F2a mating (week 41) and at the termination of the generation (week 61). 2 . Male and Female Fertility: Male and female fertility indices were compared using the Chisquare test criterion with Yates' correction for 2 x 2 contingency tables and/or Fisher's exact probability test to judge levels of significant differences. 3. Pup Survival indices: The proportion of live pups at birth per total number born and the survival indices at lactation days 4, 7, 14 and 21 were compared by the Mann-Whitney U-test to judge significant differences. 4. Litter Size and Pup Body Weights: The mean number of liveborn pups per litter and mean body weights of pups were analyzed by one-way analysis of variance, Barlett's test for homogeneity of variances, and the appropriate t- test (for equal or unequal variances). Significant differences were determined using Dunnett's multiple comparison tables. 5. Organ Weights: Absolute and relative organ weights (P/F0, F1, F2a and F2b) were compared by analysis of variance (one-way classification), Bartlett's test for homogeneity of variances and the appropriate t-test (for equal or unequal variances) using Dunnett's multiple comparision tables to judge significance of differences.

Results and discussion

Results: P0 (first parental animals)

Details on results (P0)

CLINICAL SIGNS AND MORTALITY (PARENTAL ANIMALS): With the exception of a few cases of respiratory rales, the clinical appearance and behaviour of all treated animals were not remarkably different from the controls. Mortality of adult males and females was 0 to 10% in the low and mid dose group and 65 to 70% in the high dose group.


BODY WEIGHT AND FOOD CONSUMPTION (PARENTAL ANIMALS): P/F0 body weights in the high-dose group were significantly reduced by week 11 (males: -14.1%; females: -10.4%) in both sexes and this reduction increased as the generation progressed (males: -19.7% on study week 32; females: -18%). The mid-dose group means were low but not statistically significantly different from the controls, except at the end of the generation in the females. No effects in the low dose group in either sex during both generations. No treatment-related effects on food consumption were observed in any group during the study (a slight decrease in mean female food consumption (both g/rat/day and g/kg/day) was observed throughout the P/F0 generation in the 20 mg/kg/day group, but this was considered as not treatment-related.


GROSS PATHOLOGY (PARENTAL ANIMALS)/HISTOPATHOLOGY (PARENTAL ANIMALS): Macroscopic and microscopic examination of tissues from P/F0 adults revealed compound-related changes in the kidneys and bladder of rats from all dose groups. However, renal cortical necrosis, present in 60% of the males and in 15% of the females from this group, was only observed in the high-dose group.


OTHER FINDINGS (PARENTAL ANIMALS): Inflammatory changes were observed in stomachs of rats from all groups. Since these changes could arise by a variety of mechanisms, it was not possible to conclude they were directly related to maleic anhydride. Fertility was significantly reduced in the treatment groups at several time points; however, neither a dose-related reduction nor a pattern within a generation suggested a treatment-related effect (male and female fertility indices were reduced in the 20 and 150 mg/kg/day groups in the F1a mating when compared with the control group. The relation of these findings to treatment is doubtful since the F1b mating fertility indices were generally comparable at all treatment levels.)

Effect levels (P0)

open allclose all
Dose descriptor:
LOEL
Remarks:
(fertility)
Effect level:
20 mg/kg bw/day
Sex:
male/female
Basis for effect level:
other: reduced fertility in males and females, however, neither a dose-related reduction nor a pattern within a generation suggested a treatment-related effect (see below)
Dose descriptor:
LOAEL
Remarks:
(systemic)
Effect level:
20 mg/kg bw/day
Sex:
male/female
Basis for effect level:
other: P: Macroscopic and microscopic compound-related changes in the kidneys and bladder ; mortality 60-70% in the high dose group; F1: increased absolute kidney weights of adult females
Remarks on result:
other: Generation: P/F1 (migrated information)
Dose descriptor:
LOEL
Remarks:
(local)
Effect level:
20 mg/kg bw/day
Sex:
male/female
Basis for effect level:
other: inflammatory changes in stomachs (it was not possible to conclude they were directly related to maleic anhydride)

Results: F1 generation

Details on results (F1)

VIABILITY (OFFSPRING)/CLINICAL SIGNS (OFFSPRING):
Respiratory rales were observed and the incidence and severity appeared to increase with dose. These rats often vigorously resisted handling at the time of dosing. Some animals were difficult to treat, and gavage-related deaths were observed in F1 adults. More deaths were observed in the F1 generation than in the P/F0 generation. Most of these death were attributed to gavage related injuries. If these deaths are omitted than a 0 to 10% mortalitiy was observed in both the low and the mid dose groups and significant mortality was only observed in the high dose group. Due to 100% mortality among the high-dose F1 females by study week 42, the remaining high-dose males were terminated by study week 44.


BODY WEIGHT (OFFSPRING):
- Pup weight at birth: significantly reduced (p<0 .01) in the 150 mg/kg/day group in the F1a litters (-14%). This effect was not observed in the F1b litters.
- Pub weight during lactation: at the 150 mg/kg/day level, inhibition of pup body weight was observed throughout lactation (with statistical significance on days 7, 14 and 21 (-21%) in the F1a litters and after day 7 of lactation in the F1b litters), but there was no consistent pattern between litters in a generation or between generations that suggested a treatment-related effect).
- Parental (F1) body weight: F1 generation showed a similar pattern of depressed weight gain; however, only the F1 males in the high-dose group had significant body weight depression at 30 weeks.
- Mean maternal body weight gain (F1) during gestation in the 20 and 55 mg/kg/day groups (no 150 mg/kg treatment group due to the described mortalities of the female rats) was comparable to the control group during the F2a and F2b matings. The 20 mg/kg/day group exhibited mean maternal body weight gain in excess of the control group during lactation in the F2a mating and mean loss in maternal body weight during lactation in the F2b mating (-24%). Slight reduction of mean maternal body weight gain and no gain in mean maternal body weight were observed during lactation in the F2a and F2b matings respectively, at the 55 mg/kg/day level.


ORGAN WEIGHTS (OFFSPRING): In the F1 generation, the absolute kidney weights of adult females in the low- and mid-dose groups were significantly increased to 108 and to 111%, respectively, of the control value.


GROSS PATHOLOGY (OFFSPRING)/HISTOPATHOLOGY (OFFSPRING):
- F1: Low incidence of mineralization (2/12 males; 3/21 females) and nephrosis (2/12 males ; 5/21 females) in the kidney of animals receiving 150 mg/kg/day. There were no microscopic changes in these kidneys.
- F2: Microscopic examination of tissues from pups in the F2 litters revealed no treatment-related changes. Therefore, treatment up to 55 mg/kg/day for two generations had no adverse effect on pups.

OTHER FINDINGS (OFFSPRING): No treatment-related effects were observed on indices of fertility for males and females in the F1 generation. No adverse effects on litter size and on pup survival were observed at doses up to 150 mg/kg/day in the F1 litters, or at 55 mg/kg/day in the F2 litters.

Effect levels (F1)

Dose descriptor:
NOEL
Remarks:
(fertility)
Generation:
F1
Effect level:
55 other: mg/kg/day
Sex:
male/female
Basis for effect level:
other: No effects; highest dose tested without complete maternal mortility

Overall reproductive toxicity

Reproductive effects observed:
not specified

Applicant's summary and conclusion