Registration Dossier

Administrative data

Endpoint:
three-generation reproductive toxicity
Remarks:
based on test type (migrated information)
Type of information:
experimental study
Adequacy of study:
key study
Study period:
1976-1978
Reliability:
2 (reliable with restrictions)
Rationale for reliability incl. deficiencies:
other: Meets generally accepted scientific standards, well documented and acceptable for assessment.

Data source

Reference
Reference Type:
study report
Title:
Unnamed
Year:
1978
Report Date:
1978

Materials and methods

Test guidelineopen allclose all
Qualifier:
equivalent or similar to
Guideline:
other: U.S.F.D.A Guidelines (1966)
Deviations:
yes
Remarks:
See Overall remarks
Qualifier:
equivalent or similar to
Guideline:
OECD Guideline 416 (Two-Generation Reproduction Toxicity Study)
Deviations:
yes
Remarks:
See Overall remarks
Principles of method if other than guideline:
GUIDELINE FOLLOWED (U.S.F.D.A Guidelines (1966))F0 group consisted of 10 males and 20 females cohabited for 14 days. F1a group was discarded and the F0 group remated. Twenty to 24 apparently normal offspring (F1b) of each sex were randomly selected in approx. equal numbers from each group and mated 1 / 1 with rats from the same group.The same procedure was followed with the F2 group. The F3b group was sacrificed after weaning and the overt physical and reproductive parameters called for in the FDA Guideline were evaluated. The results are shown in the tables on the pages 4 and5. As usual, rats in each cage were examined daily.
GLP compliance:
no
Remarks:
Unlikely
Limit test:
no

Test material

Reference
Name:
Unnamed
Type:
Constituent
Details on test material:
- Name of test material (as cited in study report): Nitroglycerin, TNG- Substance type: technical product- Physical state: a 10 % mixture on lactose- Analytical purity: 9.72% +/- 0.09%- Lot/batch No.: D17-H3- Source: Atlas Chemical Division, ICI America Inc., Wilmington, DE

Test animals

Species:
rat
Strain:
other: Charles River CD
Sex:
male/female
Details on test animals and environmental conditions:
TEST ANIMALS- Source: Charles River Breeding Laboratory, Wilmington, Massachusetts, USA- Age at study initiation: All animals were maturing- Fasting period before study: no data- Housing: plastic cages with metal lids, filter tops, 4 male or 5 female in each cage, some groups were subdivided to prevent fighting.- Identification of animals: ear-punches- Bedding: with hardwood chip- Diet: ad libitum, Diets were prepared weekly- Water: ad libitum- Acclimation period: 2 weeksENVIRONMENTAL CONDITIONS- Temperature (°F): 75+/-5- Humidity (%): 50+/-10%- Air changes (per hr): 10 air changes per hour- Photoperiod (hrs dark / hrs light):12 hour light/12 hour dark

Administration / exposure

Route of administration:
oral: feed
Vehicle:
unchanged (no vehicle)
Details on exposure:
With the rodents, dosage levels of 0,01% (100 ppm), 0,1% (1000 ppm) and 1% (10 000 ppm) in the diet were used.DIET PREPARATION- Rate of preparation of diet (frequency): Diets were prepared weekly. - Mixing appropriate amounts with (Type of food): 10% concentrate was mixed with feed in a rotating box on a modified mixer to provide the diet mixture by successive dilutions. The control rodents received a mixture containing 10% dried feed in ordinary feed.With the rodents, dosage levels of 0,01% (100 ppm), 0,1% (1000 ppm) and 1% (10 000 pm) in the diet werer used.
Details on mating procedure:
- Length of cohabitation: Mating periods for F1 and F2 generations were 14 – 15 days.Reproductive performance for each parental generation was quantified by: the mating ratio and fertility ratios of each sex.- Proof of pregnancy: vaginal smears- Each male was housed with two females for 14 days.
Analytical verification of doses or concentrations:
yes
Details on analytical verification of doses or concentrations:
Test levels of diet were prepared fresh weekly by dilution of the concentrate with unheated feed and were analyzed after preparation. Control analyses were carried out over eight-day periods to measure evaporation of NG from the diet under cage conditions during the week. GC also was used for these analyses, but with a 63Ni detector. This information was used to calculate actual dosage received by the rats.
Duration of treatment / exposure:
six months for males and five months for females
Frequency of treatment:
daily in the diet
Doses / concentrations
Remarks:
Doses / Concentrations:0.0, 0.01, 0.1, and 1.0 % (w/w) in the diet. Basis:actual ingested
No. of animals per sex per dose:
The begining number of rats was 38 of each sex per group. Additional rats were icluded for the three-generation (20 females in each dosage group) and metabolism (12 males and 12 females, each in the control, low doasge and high dose group) studies.
Control animals:
yes
Details on study design:
DOSES: 0.0, 0.01, 0.1, and 1.0 % (w/w) in the diet. Corresponding average TNG intakes for six months pretreatment (six months for males and five months for females) were, respectively, 0.00(M & F); 3.60 ± 0.28(M), 5.00 ± 0.17(F); 39.0 ± 1.8(M), 46.0 ± 0.9(F); and 408 ± 18(M), 452 ± 9(F) mg TNG / kg of rat / day. Females were dosed during pregnancy and between matings. Males were dosed until successful delivery of each "b" generation

Examinations

Litter observations:
litter size, the livebornindex, the weight of liveborn pups at birth, viability index, the weight at weaning and sex ratio.

Results and discussion

Results: P0 (first parental generation)

Effect levels (P0)

Remarks on result:
not measured/tested

Results: P1 (second parental generation)

Effect levels (P1)

Remarks on result:
not measured/tested

Results: F1 generation

General toxicity (F1)

Mortality / viability:
mortality observed, treatment-related
Body weight and weight changes:
effects observed, treatment-related

Details on results (F1)

The F2a males were impotent was strengthened by the observations that 1) their testes were ~25 % of the normal size, 2) they had produced a large number of vaginal plugs without sperm, and 3) microscopic examination of slides prepared from their testes revealed severe aspermatogenesis and mild-moderate increases in the amounts of interstitial tissue in their testes. All litter parameters except male / female ratios were reduced in the high dose F1a litters. Most parameters also were somewhat reduced in the high dose F1b and F2a litters. The food intake of the F1b dams was ~65 % that of the corresponding control dams. Their gestational product (litter size x litter weight) was ~62 % that of those control dams.

Effect levels (F1)

open allclose all
Dose descriptor:
NOEL
Generation:
F1a
Effect level:
39 mg/kg bw/day (actual dose received)
Sex:
male
Basis for effect level:
other: Dietary intakes of 39 ± 1.8 mg TNG / kg / day were no-effect levels for males.
Dose descriptor:
NOEL
Generation:
F1a
Effect level:
46 mg/kg bw/day (actual dose received)
Sex:
female
Basis for effect level:
other: Dietary intakes of 46 ± 0.9 mg TNG / kg / day were no-effect levels for females.

Overall reproductive toxicity

Reproductive effects observed:
not specified

Applicant's summary and conclusion

Conclusions:
The high dose (1.0 % in the diet; 6-month average daily male intake = 408 mg ± 18 mg TNG / kg / day) caused severe aspermatogenesis with resulting severe infertility in the F2a generation of males. The high dose in the females (452 ± 9 mg TNG / kg / day caused a slight reduction in the parameters measured in the high dose F1b litter. Measurement of the dams' food intake during the F1b gestation period indicated a 35 % reduction of food intake vs. the control rats. This probably was responsible for the 38 % reduction in the individual total litter weights observed in the high dose F1b litter.Negative dominant lethal mutagenic and teratogenic studies (Robust Summaries included in this set), suggested strongly that these reduced litter parameters were not due to mutagenic or teratogenic effects as measured by those studies in intact rodents.Male daily dietary intake of an average 408 ± 18 mg TNG / kg / day was an effect level in male rats as measured by aspermatogenesis in the F2 generation of males. Female dietary intake of 452 ± 9 mg TNG / kg / day was an effect level in females as measured by litter size and birth weights. Dietary intakes of 39 ± 1.8 and 46 ± 0.9 mg TNG / kg / day, respectively, were no-effect levels for males and females.