Registration Dossier

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:
1997
Report Date:
1997

Materials and methods

Test guideline
Qualifier:
according to
Guideline:
OECD Guideline 474 (Mammalian Erythrocyte Micronucleus Test)
GLP compliance:
yes (incl. certificate)
Remarks:
BASF
Type of assay:
other: mammalian micronucleus assay in vivo

Test material

Reference
Name:
Unnamed
Type:
Constituent
Specific details on test material used for the study:
SOURCE OF TEST MATERIAL
- Source and lot/batch No.of test material: 3043/V9Z

Test animals

Species:
mouse
Strain:
NMRI
Sex:
male/female
Details on test animals and environmental conditions:
TEST ANIMALS
- Source: Charles River GmbH, WIGA, Sulzfeld, FRG
- Assigned to test groups randomly: yes
- Fasting period before study: no
- Housing: small groups for acclimatization, individually after administration
- Identifications of animals: cage cards
- Diet: (Kliba Haltungsdiät, Klingentalmühle AG, Kaiseraugst, Switzerland; ad libitum
- Water: from bottles, ad libitum
- Acclimation period: 1 week

ENVIRONMENTAL CONDITIONS
- Temperature: 20 – 24°C
- Humidity: 30-70 %
- Air changes (per hr): fully air-conditioned
- Photoperiod (hrs dark / hrs light): 12 h / 12 h

Administration / exposure

Route of administration:
oral: gavage
Vehicle:
water
Details on exposure:
PREPARATION OF DOSING SOLUTIONS: immediately before administration; all concentrations were administered at 10 mL volume.

Frequency of treatment:
single treatment
Post exposure period:
24 h (all concentrations and controls); 48 h (negative control and 2000 mg/kg)
Doses / concentrationsopen allclose all
Dose / conc.:
0 mg/kg bw/day (actual dose received)
Dose / conc.:
500 mg/kg bw/day (actual dose received)
Dose / conc.:
1 000 mg/kg bw/day (actual dose received)
Dose / conc.:
2 000 mg/kg bw/day (actual dose received)
No. of animals per sex per dose:
5/sex (vehicle ctrl.; all dose groups) 5 animals (2 males and 3 females or 3 males and 2 females) for pos. ctrl.
Control animals:
yes, concurrent vehicle
Positive control(s):
As a positive control, 20 mg of cyclophosphamide (CPP)/kg body weight or 0.15 mg of vincristine sulphate (VCR)/kg body weight, both, dissolved in purified water, were administered to male and female animals once orally or intraperitoneally each in a volume of 10 mL/kg body weight.

Examinations

Tissues and cell types examined:
erythrocytes of the femural bone marrow
Details of tissue and slide preparation:
CRITERIA FOR DOSE SELECTION: The respective OECD guideline suggests 2000 mg/kg bw as the highest dose. In a pretest, all animals survived this dosage.

DETAILS OF SLIDE PREPARATION: Bone marrow was prepared from the femura and transferred onto microscopic slides using a standard protocol. The resulting slides were stained with eosin-methylene blue and Giemsa and finally embedded in Corbit-Balsam.

METHOD OF ANALYSIS: 2000 polychromatic erythrocytes were counted for each animal. The number of nor-chromatic erythrocytes was scored, too.

Evaluation criteria:
The test chemical is to be considered positive in this assay if the following criteria are met: A dose-related and significant increase in the number of micronucleated polychromatic erythrocytes at any of the intervals. The proportion of cells containing micronuclei exceeded both the values of the concurrent negative control range and the negative historical control range.
A test substance is generally considered negative in this test system if: There was no significant increase in the number of micronucleated polychromatic erythrocytes at any dose above concurrent control frequencies and at any time. The frequencies of cells containing micronuclei were within the historical control range.
Statistics:
Statistical evaluation of data: MUKERN (BASF AG).
Comparison of dose groups: One-sided Wilcoxon test for the hypothesis of equal medians.

Results and discussion

Test results
Key result
Sex:
male/female
Genotoxicity:
negative
Toxicity:
no effects
Vehicle controls validity:
valid
Negative controls validity:
not applicable
Positive controls validity:
valid
Additional information on results:
No inhibition of erythropoiesis was observed.

Applicant's summary and conclusion