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Toxicological information

Genetic toxicity: in vivo

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Administrative data

Endpoint:
in vivo mammalian somatic cell study: cytogenicity / erythrocyte micronucleus
Type of information:
experimental study
Adequacy of study:
key study
Reliability:
1 (reliable without restriction)
Rationale for reliability incl. deficiencies:
guideline study

Data source

Reference
Reference Type:
study report
Title:
Unnamed
Year:
1995
Report date:
1996

Materials and methods

Test guidelineopen allclose all
Qualifier:
according to guideline
Guideline:
OECD Guideline 474 (Mammalian Erythrocyte Micronucleus Test)
Qualifier:
according to guideline
Guideline:
EU Method B.12 (Mutagenicity - In Vivo Mammalian Erythrocyte Micronucleus Test)
GLP compliance:
yes (incl. QA statement)
Type of assay:
micronucleus assay

Test material

Constituent 1
Reference substance name:
Donor C20
IUPAC Name:
Donor C20
Test material form:
solid: particulate/powder
Remarks:
migrated information: powder

Test animals

Species:
mouse
Strain:
Swiss
Sex:
male/female
Details on test animals or test system and environmental conditions:
TEST ANIMALS
- Source: Charels River Wiga GmbH
- Age at study initiation: young adult mice
- Assigned to test groups randomly: computer randomisation
- Housing: males housed individually, females were housed in groups of 5 per cage
- Diet (e.g. ad libitum): ad libitum
- Water (e.g. ad libitum): ad libitum


ENVIRONMENTAL CONDITIONS
- Temperature (°C): 22 +/- 3C
- Humidity (%): 30 - 72%
- Air changes (per hr): 10
- Photoperiod (hrs dark / hrs light): 12

IN-LIFE DATES: From: 7 November 1995 To: 8,9,10 November 1995

Administration / exposure

Route of administration:
oral: gavage
Vehicle:
maize oil
Details on exposure:
PREPARATION OF DOSING SOLUTIONS: Test substance was dissolved in maize oil one day prior to use.
Duration of treatment / exposure:
1 gavage dose
Post exposure period:
Signs of reactions to treatment were recorded from ca. 1 - 4 hours after treatment and daily thereafter. At 24, 48, and 72h post-treatment, 10 controls (5m/5f) and 10 test animals (5m/5f) were killed by cervical dislocation. At 24h the 5 positive control animals were sacrificed. Bone marrow was immediately collected into foetal calf serum and processed into glassdrawn smears. Two bone marrow smears per animal were prepared, air-dried, fixed in methanol and stained with May-Brunwald Giemsa.
Doses / concentrations
Dose / conc.:
2 000 mg/kg bw (total dose)
Remarks:
nominal concentration
No. of animals per sex per dose:
5 males/ 5 females
Positive control(s):
Mitomycin C (0.75 mg/kg bw)

Examinations

Tissues and cell types examined:
Bone marrow smears onto glass slides
Details of tissue and slide preparation:
At sacrifice: Bone marrow was immediately collected into foetal calf serum and processed into glassdrawn smears. Two bone marrow smears per animal were prepared, air-dried, fixed in methanol and stained with May-Brunwald Giemsa.
Evaluation criteria:
The number of polychromatic erythrocytes per 1000 erythrocytes and the number of micronucleated polychromatic erythrocytes per 1000 polychromatic erythrocutes from the vehicle control and treatment group were analysed using three-way ANOVA with factors sex, group, and time.
Statistics:
Because the three way ANOVA yielded significant effects, the negative control group (A) was compared with the treatment group (B), using two sided asymptotic t-tests for each sex and time point. If the criteria for homogeneity of variances was not met (Leven's test), Brown-Forsythe ANOVA was used followed by separate variance t-tests.

Results and discussion

Test results
Sex:
male/female
Genotoxicity:
negative
Toxicity:
yes
Vehicle controls validity:
valid
Positive controls validity:
valid
Additional information on results:
In male mice treated with test compound, the number of PE per 1000 E was not statistically different than those found in vehicle controls, indicating that the treatment did not result in cytotoxicity to bone marrow cells. In female mice only at 48h was the number of PE per 1000 E statistically significantly lower than those found in the vehicle controls, indicating that the treatment resulted in cytotoxicity to bone marrow cells.

Applicant's summary and conclusion

Conclusions:
No indication of chromosomal damage and/or damage to the mitotic apparatus in bone marrow cells of mice treated by gavage with 9,9-bis(methoxymethyl)fluorene at a dose level of 2000 mg/kg (limit dose)