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Toxicological information

Genetic toxicity: in vivo

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Administrative data

Endpoint:
in vivo mammalian germ cell study: cytogenicity / chromosome aberration
Remarks:
Type of genotoxicity: chromosome aberration
Type of information:
migrated information: read-across based on grouping of substances (category approach)
Adequacy of study:
key study
Reliability:
2 (reliable with restrictions)
Rationale for reliability incl. deficiencies:
other: see 'Remark'
Remarks:
Study conducted according to internationally accepted testing guidelines, are well documented and scientifically acceptable. Justification for Read Across is reported in the endpoint summary and in the Category Justification Report attached to the Section 13 of this dossier.

Data source

Referenceopen allclose all

Reference Type:
study report
Title:
Unnamed
Year:
1973
Report Date:
1973
Reference Type:
publication
Title:
Testing Mutagenic Properties with the Dominant Lethal Test on the Male Mouse.
Author:
D. Lorke and L. Machemer
Year:
1975
Bibliographic source:
Environmental Quality and Safety, Suppl. Vol. 4, 239-246

Materials and methods

Test guideline
Qualifier:
equivalent or similar to
Guideline:
OECD Guideline 478 (Genetic Toxicology: Rodent Dominant Lethal Test)
GLP compliance:
not specified
Remarks:
pre GLP
Type of assay:
rodent dominant lethal assay

Test material

Reference
Name:
Unnamed
Type:
Constituent

Test animals

Species:
mouse
Strain:
NMRI
Sex:
male
Details on test animals and environmental conditions:
TEST ANIMALS
- Source: S. Ivanovas GmbH, Kisslegg, Germany.
- Age at study initiation: about 10 weeks.
- Weight at study initiation: mean: male: 30-35g, female: 25-30g.
- Housing: single.
- Diet: ad libitum.
- Water: ad libitum.

ENVIRONMENTAL CONDITIONS
- Temperature: 24 - 26 °C
- Humidity: about 60 %

Administration / exposure

Route of administration:
oral: gavage
Vehicle:
- Vehicle used: water + 1 % Traganth.
Details on exposure:
PREPARATION OF DOSING SOLUTIONS: suspension
Duration of treatment / exposure:
Single dosage.
Frequency of treatment:
Once.
Doses / concentrations
Remarks:
Doses / Concentrations:
5000 mg/kg bw
Basis:
actual ingested
No. of animals per sex per dose:
20 males and 480 females.
Control animals:
yes, concurrent vehicle
Positive control(s):
Methylmethanesulfonate (MMS) and trimethyl phosphate (TMPO)
- Route of administration: MMS: ip and TMPO: oral - gavage
- Doses / concentrations: MMS = 100 mg/kg and TMPO = 1000 mg/kg

Examinations

Tissues and cell types examined:
Number of fertile matings, implantation, resorption, live foetuses, and corpora lutea.
Statistics:
The χ2-test, the t-test or the distribution-free rank sum test (Wilcoxon) were used to assess the results.

Results and discussion

Test results
Sex:
male
Genotoxicity:
negative
Toxicity:
no effects
Vehicle controls validity:
not examined
Negative controls validity:
valid
Positive controls validity:
valid

Any other information on results incl. tables

Fertilization

There were no significant differences between the untreated controls and the groups treated with the test substance. The results also showed that TMPO treatment had no effect. MMS, on the other hand, considerably reduced the ability of the male to fertilize the female in the first two weeks of mating.

Pre-implantation losses

Treatment with the test substance did not cause a biologically significant increase in preimplantation losses. This is also shown by comparing the implantation rates, from which pre-implantation losses can be estimated. Similarly TMPO did not increase pre-implantation losses. MMS, however clearly increased pre-implantation losses during the first week and - as can be seen from the number of implantations per female - even caused pre-implantation losses of embryos during the second and third week of mating.

Post-implantation losses

The results did not differ significantly from those of the controls for any of the mating weeks. TMPO, however, caused a marked increase in post-implantation losses in the second mating week, and MMS in the first and second weeks. This led to a decrease in the number of live foetuses during these weeks.

Dominant lethal mutations

The test substance did not cause dominant lethal mutations. TMPO was effective in the second mating week. MMS had a marked effect in the first two weeks and it was probably also effective to a lesser extent in the third week.

Applicant's summary and conclusion

Conclusions:
Interpretation of results (migrated information): negative
The dominant lethal test investigation did not shown any evidence of mutagenicity caused by the test substance.
Executive summary:

Method

The compound was administered orally in single dose to NMRI mice by gavage at the concentration of 5000 mg/kg. Methylmethanesulfonate (MMS) and trimethyl phosphate (TMPO) were used as positive controls.

Each of the 20 male mice in each group was mated with three untreated females directly after treatment. After insemination (determined by vaginal smear), or after a week, the females were isolated. This procedure was repeated weekly for eight weeks.

On the fourteenth day of gestation the females were sacrificed and the numbers of fertile matings, implantations, resorptions, live foetuses, and corpora lutea were determined.

Results

There were no significant differences between the untreated controls and the groups treated with the test substance. Treatment with the test substance did not cause a biologically significant increase in preimplantation losses and the results did not differ significantly from those of the controls for any of the mating weeks.

The test substance did not cause dominant lethal mutations.