Registration Dossier

Administrative data

Endpoint:
in vivo mammalian somatic cell study: cytogenicity / erythrocyte micronucleus
Remarks:
Type of genotoxicity: chromosome aberration
Type of information:
experimental study
Adequacy of study:
key study
Reliability:
1 (reliable without restriction)
Rationale for reliability incl. deficiencies:
other: GLP-compliant near-guideline study, no restrictions, fully adequate for assessment.

Data source

Referenceopen allclose all

Reference Type:
study report
Title:
Unnamed
Year:
1989
Report Date:
1989
Reference Type:
publication
Title:
Unnamed
Year:
1995

Materials and methods

Test guideline
Qualifier:
equivalent or similar to
Guideline:
OECD Guideline 474 (Mammalian Erythrocyte Micronucleus Test)
GLP compliance:
yes
Type of assay:
micronucleus assay

Test material

Reference
Name:
Unnamed
Type:
Constituent
Details on test material:
- Name of test material (as cited in study report): MRD-89-374
- Physical state: colourless liquid
- Analytical purity: 93%
- Lot/batch No.: 1

Test animals

Species:
mouse
Strain:
CD-1
Sex:
male/female
Details on test animals and environmental conditions:
TEST ANIMALS
- Source: Charles River Breeding Laboratories
- Age at study initiation: 7 weeks
- Weight at study initiation: 23-38 gram
- Housing: single
- Diet : ad libitum
- Water: ad libitum
- Acclimation period: 19 days


ENVIRONMENTAL CONDITIONS
- Temperature: 68-76°F
- Humidity (%): 40-70
- Photoperiod (hrs dark / hrs light): 12/12

Administration / exposure

Route of administration:
intraperitoneal
Vehicle:
corn oil
Details on exposure:
Negative control and TAME treated animals formed three different sample time groups (24, 48 and 72 hours), consisting of five mice of each sex per group. Animals dosed with cyclophosphamide were taken at 24 hours only.

The doses were selected based on a preliminary toxicity test in which there was mortality still at 1000 mg/kg dose, 750 mg/kg was found to be the highest non-toxic concentration.
Duration of treatment / exposure:
single intraperitoneal injection
Frequency of treatment:
single intraperitoneal injection
Post exposure period:
24, 48 and 72 hours
Doses / concentrations
Remarks:
Doses / Concentrations:
150, 375 or 750 mg/kg body weight
Basis:
other: single i.p. dose
No. of animals per sex per dose:
10 (5/sex/dose)
Control animals:
yes, concurrent vehicle
Positive control(s):
Positive control (cyclophosphamide, 40 mg/kg bw) mice were sampled at 24 hours only.

Examinations

Tissues and cell types examined:
Both femurs from each animal were removed and bone marrow was recovered.
Details of tissue and slide preparation:
Bone marrow as suspended in fetal bovine serum. Following centrifugation to pellet the tissue, the supernatant was drawn off, the pellet resuspended and the suspension spread on slides and dried (two slides were prepared per animal). Prior to microscopic evaluation, the slides were stained using acridine orange.
Evaluation criteria:
Bone marrow smears were prepared from femurs:
- 1000 polychromatic erythrocytes (PCE) were examined for micronuclei;
- the ratio of PCE and normochromatic erythrocytes (NCE) was calculated from 1000 erythrocytes.
Statistics:
A standard one way analysis of variance and regression analysis were performed.

Results and discussion

Test results
Sex:
male/female
Genotoxicity:
negative
Toxicity:
no effects
Vehicle controls valid:
yes
Negative controls valid:
not examined
Positive controls valid:
yes
Additional information on results:
All mice survived to scheduled termination. No increase in micronucleus frequency was observed at any dose level. Overt marrow toxicity was not observed (measured by a decrease in the percentage of PCEs). The percentages of PCEs observed were within the normal range.

Applicant's summary and conclusion