Registration Dossier

Toxicological information

Developmental toxicity / teratogenicity

Currently viewing:

Administrative data

Endpoint:
developmental toxicity
Type of information:
experimental study
Adequacy of study:
key study
Study period:
11 Mai - 24 Jun 1982
Reliability:
2 (reliable with restrictions)
Rationale for reliability incl. deficiencies:
other: Comparable to guideline study

Data source

Reference
Reference Type:
study report
Title:
Unnamed
Year:
1983
Report Date:
1983

Materials and methods

Test guideline
Qualifier:
equivalent or similar to
Guideline:
OECD Guideline 414 (Prenatal Developmental Toxicity Study)
Deviations:
yes
Remarks:
test substance was administered solely in the period of GD 6-15
GLP compliance:
not specified
Limit test:
yes

Test material

Reference
Name:
Unnamed
Type:
Constituent

Test animals

Species:
rat
Strain:
other: Crl:COBS, CD® (SD) BR
Details on test animals and environmental conditions:
TEST ANIMALS
- Source: Charles River Breeding Laboratories, Inc., Kingston, New York, USA
- Age at study initiation: approx. 14 weeks (mating age)
- Housing: individually in elevated wire-mesh cages
- Diet: Purina Rodent Laboratory Chow ®, ad libitum
- Water: tap water, ad libitum
- Acclimation period: 9 weeks

ENVIRONMENTAL CONDITIONS
- Temperature (°C): approx. 24
- Humidity (%): 57 ± 4.8
- Photoperiod (hrs dark / hrs light): 12 / 12

IN-LIFE DATES: From: 11 Mai 1982 To: 24 Jun 1982

Administration / exposure

Route of administration:
oral: gavage
Vehicle:
corn oil
Details on exposure:
PREPARATION OF DOSING SOLUTIONS:
Dosing solutions were prepared weekly by mixing appropriate amounts of the test item with corn oil on a magnetic stirrer (g/v) and transferred to amber bottles. The prepared dilutions were well shaken before use and animals were dosed while solutions were mixed on a magnetic stirrer.

Dosing volumes were based on individual body weights from the most weighing interval. Day 15 dosing was based on the body weight of Day 12.


Analytical verification of doses or concentrations:
not specified
Details on mating procedure:
- Impregnation procedure: cohoused
- M/F ratio per cage: 1/2
- Length of cohabitation: up to 3 weeks
- After 10 days, females were rotated
- Proof of pregnancy: vaginal plug or sperm in vaginal smear referred to as day 0 of pregnancy
Duration of treatment / exposure:
Day 6 - 15 of gestation
Frequency of treatment:
daily, 7 days/week
Duration of test:
20 days (GD 0-20)
Doses / concentrations
Dose / conc.:
1 000 mg/kg bw/day (actual dose received)
No. of animals per sex per dose:
22 females
Control animals:
yes, concurrent vehicle
Details on study design:
- Dose selection rationale: The applied dose showed no maternal toxicity in a previous dose-range finding study (1982).

Examinations

Maternal examinations:
CLINICAL OBSERVATIONS: Yes
- Time schedule: daily
- Parameters checked: e.g. alopecia, bloody crust, wheezing, labored respiration, urine stains, rough haircoat, stains on fur, salivation, corneal defect, wasting feed, water spillage, hunched, dyspnea, red discharge from vagina, soft feces

BODY WEIGHT: Yes
- Time schedule for examinations: days 0, 6, 9, 12, 15 and 20 of gestation

FOOD CONSUMPTION : Yes
- Food consumption for each animal determined and mean daily diet consumption calculated as g food: Yes
- Time schedule for examinations: Days 6 - 8, 9 - 11, 12 - 14, 15 - 17 and 18 - 20 of gestation

WATER CONSUMPTION: Yes
- Time schedule for examinations: Days 6 - 8, 9 - 11, 12 - 14, 15 - 17 and 18 - 20 of gestation

POST-MORTEM EXAMINATIONS: Yes
- Sacrifice on gestation day 20
- Organs examined: uterus, oavary, cecum, lung, kidney, stomach, liver, pancreas, adrenals, brain, pituitary, thymus, spleen, eyes, lymph nodes (mesenteric, cervical, mandibular)

Ovaries and uterine content:
The ovaries and uterine content was examined after termination: Yes
Examinations included:
- Gravid uterus weight: Yes
- Number of corpora lutea: Yes
- Number of implantations: Yes
- Number resorptions: Yes (early and late resorptions)
- Other: Nongravid uterine weights (with ovaries attached): Yes
Fetal examinations:
- External examinations: Yes: [all per litter]
- Skeletal examinations: Yes: [two-third per litter]
- Other: Visceral examinations: Yes [one-third per litter]; body weight and crown-rump distance [all per litter]
Statistics:
Mean values and standard deviations were calculated from the examined parameters.
Survival was analysed by the National Cancer Institute Package (Tomas, Breslow and Gart, 1977). The mean maternal body weight changes (days 0 - 6, 6 - 15, 15 - 20 and 0 - 20), mean maternal food and water consumptions), percent males per litter, mean fetal body weights and lengths, fetal viability, percent resorptions, implantation efficiency, gravid and non-gravid uterine weights and the incidence of visceral and skeletal anomalies and variants were analysed by Box´s test for homogeneity of variances. This test was followed by one-way classification analysis of variance (ANOVA) if the variances proved to be homogeneous. If the variances proved to be heterogeneous, a rank transformation of data was performed, which was followed by Box´s test and ANOVA. If ANOVA of untransformed or transformed data was significant, a Dunnett´s T-Test was used for control vs treatment group mean comnparisons. Pregnancy rates were analysed by a test of multiple proproportions using one degree of freedom Chi-square test with Yate´s continuity correction (Fleiss 1981). All pairwise comparisons were evaluated at the 0.5% probability (one-tailed) level.
Indices:
Mean incidence of resorptions (%): group mean of [(resorptions per litter/implantations per litter) x 100]
Mean incidence of fetal mortality (%): group mean of [(dead fetuses per litter/implantations per litter) x 100]
Mean incidence of fetal viability (%): group mean of [(live fetuses per litter/implantations per litter) x 100]
Mean incidence of visceral anomalies(%): group mean of [(number fo fetuses with anomalies per litter/number of fetuses examined viscerally per litter) x 100]
Mean incidence of visceral variants (%): group mean of [(number fo fetuses with variants per litter/number of fetuses examined viscerally per litter) x 100]
Mean incidence of skeletal anomalies (%): group mean of [(number fo fetuses with anomalies per litter/number of fetuses examined skeletally per litter) x 100]
Mean incidence of skeletal variants (%): group mean of [(number fo fetuses with variants per litter/number of fetuses examined skeletally per litter) x 100]

Results and discussion

Results: maternal animals

General toxicity (maternal animals)

Clinical signs:
effects observed, non-treatment-related
Description (incidence and severity):
effects were considered incidental
Mortality:
mortality observed, non-treatment-related
Description (incidence):
one female died, not considered treatment-related
Body weight and weight changes:
no effects observed
Food consumption and compound intake (if feeding study):
no effects observed
Food efficiency:
not examined
Water consumption and compound intake (if drinking water study):
no effects observed
Ophthalmological findings:
not examined
Haematological findings:
not examined
Clinical biochemistry findings:
not examined
Urinalysis findings:
not examined
Behaviour (functional findings):
not examined
Immunological findings:
not examined
Organ weight findings including organ / body weight ratios:
not examined
Gross pathological findings:
effects observed, non-treatment-related
Description (incidence and severity):
effects were considered incidental
Neuropathological findings:
not examined
Histopathological findings: non-neoplastic:
not examined
Histopathological findings: neoplastic:
not examined

Maternal developmental toxicity

Number of abortions:
no effects observed
Pre- and post-implantation loss:
no effects observed
Total litter losses by resorption:
not specified
Early or late resorptions:
not specified
Dead fetuses:
no effects observed
Changes in pregnancy duration:
not examined
Description (incidence and severity):
Migrated Data from removed field(s)
Field "Effects on pregnancy duration" (Path: ENDPOINT_STUDY_RECORD.DevelopmentalToxicityTeratogenicity.ResultsAndDiscussion.ResultsMaternalAnimals.MaternalDevelopmentalToxicity.EffectsOnPregnancyDuration): not examined
Changes in number of pregnant:
no effects observed
Details on maternal toxic effects:
MORTALITY AND CLINICAL OBSERVATIONS
One animal in the treatment group was found dead on day 8 of gestation. However, the survival rate of treated animals (95.5%) were comparable to control (100%).
No increased incidence of clinical observations was noted. Wheezing was observed in three treated rats during GD 6-15 and in two treated rats after treatment (GD 16-20). One treated rat had a rough haircout. In the control group, alopecia (neck), corneal defect, wasting feed and water spillage was each observed in one animal.


BODY WEIGHT CHANGE, FOOD AND WATER CONSUMPTION
No effects on body weights, food and water consumption were noted. The mean body weight change (Day 0-20 of gestation) was 104.2 ± 12.5 g for the treated females compared to 106.9 ± 14.7 g for the control group. The treated rats had a total food consumption intake (Day 9 -20 of gestation) of 243.0 ± 31.3 g (controls: 249.9 ± 43.7).

GROSS PATHOLOGY
The effects noted in gross pathology examinations are present in control and test animals in low frequencies and are therefore considered to be incidential in nature and showed no relation to treatment. In detail, control and test animals revealed anomalies of the kidneys (pelvises dilated, firm nodules on surface, depressed area in cortex) and red focal areas in the lung. Further, one test animal each showed yellow areas on the liver surface, reddened/enlarged cervical lymph nodes and a thin and pale nonglandular mucosa and smooth glandular mucosa. One control animal had clear raised areas on the surface of eyes.

OTHER
The pregnancy rate was 100% in the 1000 mg/kg bw/day dose group and in control animals.
No alterations in the number of corpora lutea, implantations and mean implantation efficiencies (number of implantations per number of corpura lutea) and resorptions were observed .
Gravid and nongravid uterine weights were comparable between the control and dose group (table 1).

Effect levels (maternal animals)

Dose descriptor:
NOAEL
Effect level:
>= 1 000 mg/kg bw/day (actual dose received)
Based on:
test mat.
Basis for effect level:
other: maternal toxicity

Maternal abnormalities

Abnormalities:
no effects observed

Results (fetuses)

Fetal body weight changes:
no effects observed
Description (incidence and severity):
Migrated Data from removed field(s)
Field "Fetal/pup body weight changes" (Path: ENDPOINT_STUDY_RECORD.DevelopmentalToxicityTeratogenicity.ResultsAndDiscussion.ResultsFetuses.FetalPupBodyWeightChanges): not examined
Reduction in number of live offspring:
no effects observed
Changes in sex ratio:
no effects observed
Changes in litter size and weights:
no effects observed
Changes in postnatal survival:
not examined
External malformations:
no effects observed
Skeletal malformations:
no effects observed
Visceral malformations:
no effects observed
Details on embryotoxic / teratogenic effects:
No alterations in the number of live and dead fetuses were observed. Fetal viability, size and sex remained unchanged.
Anomalies determined in gross pathology, visceral and skeleton examinations were present in both, control and test animals and are therefore not considered as treatment-related effects (for details, see table 2).

Effect levels (fetuses)

Dose descriptor:
NOAEL
Effect level:
>= 1 000 mg/kg bw/day (actual dose received)
Based on:
test mat.
Basis for effect level:
other: teratogenicity and development

Fetal abnormalities

Abnormalities:
no effects observed

Overall developmental toxicity

Developmental effects observed:
no

Any other information on results incl. tables

Table 1: Ovarian, Uterine and Litter Data

Parameter

Control

1000 mg/kg bw/day

Mean uterine weights

Gravid

69.48 ± 13.953

67.63 ± 11.91

Mean uterine weights

Nongravid

6.52 ± 1.424a

7.04 ± 1.982a

Corpora lutea (mean number)

15.9

14.7

Implantations (number)

13.5

12.8

Mean implantation efficiency (indeces)

85.7a

88a

Resorptions (number)

1.2

0.6

Mean incidence of resorptions (%)

9.2a

4.3a

Dead fetuses (number)

0.0

0.0

Mean incidence of fetal mortality (%)

0.0a

0.0a

Live fetuses (number)

12.4 ± 2.56

12.2 ±1.91

Mean incidence of fetal viability (%)

90.8a

95.7a

Incidences were calculated on a per litter basis.

Data are shown as means.

a: Data analysed following rank transformation

 

Table 2: Examination of the fetuses

Parameter

Control

1000 mg/kg bw/day

Live fetuses

Males

Mean body weight (g)

3.58 ± 0.201b

3.46 ± 0.264b

Mean crown-rump distance (cm)

3.8 ± 0.15b

3.8 ± 0.19b

Females

 

 

Mean body weight (g)

3.39 ± 0.186b

3.32 ± 0.248b

Mean crown-rump distance (cm)

3.7 ± 0.14b

3.7 ± 0.18b

Males per litter (Mean %)

54.0 ± 18.31

47.4 ± 13.62

Gross pathology findings:

Number of fetuses examined

191

175

Number of fetuses appearing normal

169

166

Skull

0

0

Palate

0

0

Cleft palate

0

0

Heart

0

0

Kidney

0

0

Ureter

0

0

Dilated

16

7

Hydroureter

0

1

Undulated

2

1

Umbilical hernia

1

0

Situs inversus

1

0

Hindleg

0

0

Small

1

0

Exencephaly

0

0

Tail missing

0

0

Mean incidence values for visceral findings

Number of litters

22

22

Number with anomalies

0a

0.05 ± 0.213a

Incidence of anomalies (%)c

0a

1 ± 5.3a

Number with variants

0.1 ± 0.29a

0.1 ± 0.29a

Incidence of variants (%)d

3 ± 9.7a

3 ± 11.7a

Mean incidence values for skeletal findings

Number of litters

22

22

Number with anomalies

0a

0a

Incidence of anomalies (%)e

0a

0a

Number with variants

3 ± 2.3a

3 ± 2.2a

Incidence of variants (%)f

39 ± 25.2a

31 ± 24.6a

Visceral Findings

Number of fetuses examined/number of litters

81/22

80/22

Number of fetuses with anomalies/number of litters with anomalies

0/0

1/1

Number of anomalies

0

1

Hydroureter

0

1

Number of fetuses with variants/number of litters with anomalies

2/2

2/2

Number of variants

2

3

Dilated renal pelves

2

1

Dilated ureters

0

2

Fetus small

0

0

Small tongue

0

0

Skeletal Findings

 

 

Number of fetuses examined/number of litters

191/22

175/22

Number of fetuses with anomalies/number oflitters with anomalies

0/0

0/0

Number of anomalies

0

0

Number of fetuses with variants/number of litters with variants

73/19

57/18

Number of variants

110

89

Skull:

 

 

Intraparietal-incomplete ossification/nonossified

21

20

Supraoccipital-incomplete ossification/nonossified

14

11

Hyoid

25

22

Supraoccipital - nonfused

0

2

Supraoccipital - lopsided

0

0

Supraoccipital - small

0

0

Small

0

0

Nasal bones appear short

0

0

Rib cage:

 

 

Parletals – irregular edges

2

4

Ribs – angulated

2

1

Ribs – 13thpair small

1

0

Ribs – first pair small

0

0

Ribs – forked

0

0

Vertebrae:

 

 

Centra – incomplete ossification / nonossified

32

19

Centra – nonfused

10

5

Centra small

0

0

Centra – missing

0

0

Sternabrae – bipartite

1

0

Hemivertebrae

0

0

Vertebrae – less than 3 ossified

0

0

No of vertebrae below 3rdsacral

0

0

Sacral vertebrae – nonossified

0

0

Halaligned centra ans arches / caudals

0

0

Caudals – less than 3 ossified

0

1

Caudals – incomplete ossification

0

0

Arches – nonossified

0

0

Pelvis:

 

 

Pelvic girdle – incomplete ossification

1

2

Pelvic girdle – small

0

0

Pubis – incomplete ossification/nonossified

1

1

Pubis – small

0

0

Ischium – incomplete ossification / nonossified

0

0

Data are shown as mean ± standard deviations.

a: Incidences were calculated on a per litter basis.

b: Data analysed following rank transformation

c: Mean Incidence of Visceral Anomalies (%) – Group mean of ((number of fetuses with anomalies per litter/number of fetuses examined viscerally per litter)x100)

d: Mean Incidence of Visceral Variance (%) – Group mean of ((number of fetuses with variants per litter/number of fetuses examined viscerally per litter)x100)

e: Mean Incidence of Skeletal Anomalies (%) – Group mean of ((number of fetuses with anomalies per litter/number of fetuses examined skeletally per litter)x100)

f: Mean Incidence of Skeletall Variance (%) – Group mean of ((number of fetuses with variants per litter/number of fetuses examined skeletally per litter)x100)

Applicant's summary and conclusion