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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
Remarks:
Type of genotoxicity: chromosome aberration
Type of information:
experimental study
Adequacy of study:
key study
Study period:
1977
Reliability:
2 (reliable with restrictions)
Rationale for reliability incl. deficiencies:
comparable to guideline study with acceptable restrictions

Data source

Reference
Reference Type:
study report
Title:
Unnamed
Year:
1977
Report Date:
1977

Materials and methods

Test guideline
Qualifier:
equivalent or similar to
Guideline:
OECD Guideline 474 (Mammalian Erythrocyte Micronucleus Test)
Deviations:
no
GLP compliance:
no
Type of assay:
micronucleus assay

Test material

Reference
Name:
Unnamed
Type:
Constituent
Details on test material:
- Substance type: Organic
- Physical state: Solid

Test animals

Species:
hamster, Chinese
Strain:
not specified
Sex:
male/female
Details on test animals and environmental conditions:
TEST ANIMALS
- Source: Fa. A. THOMAE, D-Biberach a.d.Riss
- Weight at study initiation: 23-31 g (females), 24-33 g (males)
- Diet (e.g. ad libitum): NAFAG No.196
- Water (e.g. ad libitum): Ad libitum

ENVIRONMENTAL CONDITIONS
- Temperature (°C): 23 ± 1
- Humidity (%): 55 ± 5
- Photoperiod (hrs dark / hrs light): 12/12

Administration / exposure

Route of administration:
oral: gavage
Vehicle:
- Vehicle(s)/solvent(s) used: CMC (carboxymethyl cellulose)
- Concentration of test material in vehicle: 500, 1000, and 2000 mg/kg in 20 mL/kg solution
- Amount of vehicle (if gavage or dermal): 5 % in 20 mL/kg solution
Duration of treatment / exposure:
2 days
Frequency of treatment:
daily
Post exposure period:
24 h after the second application the animals were sacrificed.
Doses / concentrationsopen allclose all
Dose / conc.:
500 mg/kg bw/day
Dose / conc.:
1 000 mg/kg bw/day
Dose / conc.:
2 000 mg/kg bw/day
No. of animals per sex per dose:
3
Control animals:
yes, concurrent vehicle
Positive control(s):
cyclophosphamide
- Route of administration: oral
- Doses / concentrations: 2 / 128 mg/kg

Examinations

Tissues and cell types examined:
Bone marrow from both femurs
Details of tissue and slide preparation:
Bone marrow was harvested from the shafts of both femurs. In a siliconized pipette filled with 0.5 μL rat serum the bone marrow was drawn up. In order to receive a homogeneous suspension the content of pipette was aspirated gently about three times. Small drops of the mixture were transferred on the end of a slide, spread out by pulling it behind a polished cover glass and the preparations were air-dried. At the next day the slides were stained in undiluted May-Grunwald solution for 2 min then in May-Grimwald solution/water 1/1 for 2 min subsequently with Giemsa solution 40% for 20 min. After having been rinsed i n methanol 55 % for 5-8 sec and subsequently with distilled water the air-dried slides were cleared in Xylol and mounted in Eukitt.
Evaluation criteria:
1000 bone marrow cells were scored from each animal and the following anomalies were registered:
a) Single Jolly bodies,
b) fragments of nuclei in erythrocytes ,
c) micronuclei in erythroblasts ,
d) micronuclei in leucopoietic cells,
e) polyploid cells
Statistics:
The significance of difference was assessed by χ2 -test.

Results and discussion

Test results
Sex:
male/female
Genotoxicity:
negative
Toxicity:
not specified
Vehicle controls validity:
valid
Negative controls validity:
not examined
Positive controls validity:
valid
Additional information on results:
In all dosage groups the percentage of cells displaying anomalies of nuclei did not differ significantly from the negative control. By contrast, the positive control (cyclophosphamide, 128 mg/kg) yielded a marked increase of the percentage of cells with anomalies. Here the mean percentage of anomalies was 4.27, whereas the negative control yielded a percentage of 0.10. The difference is highly significant (p<0.05).

Any other information on results incl. tables

The effect of the test article and cyclophosphamide on bone marrow cells of Chinese hamster. Percent of cells with anomalies of nuclei


Treatment










Control Cyclophosphamide test substance

0.5 % CMC 64 mg/kg 500 mg/kg 1000 mg/kg 2000 mg/kg
Number and sex of animals
1 2 3 4 5 6 1 2 3 4 5 6 1 2 3 4 5 6 1 2 3 4 5 6 1 2 3 4 5 6
Single Jolly bodies 0.1 0.1

0.2 0.1 3.8 3.0 2.2 3.0 3.5 2.5
0.1 0.1 0.1 0.2

0.2 0.1
0.2

0.1 0.2 0.2

Fragments of nuclei in erythrocytes





0.4 0.5 0.3 0.8 0.8 0.4

















Micronuclei in erythroblasts





0.9 0.1 0.2 0.4 0.7 0.6

















Micronulclei in leucopoieetic cells


























0.1

Polyploid cells
0.1



0.5 0.3 0.1 0.2 0.3 0.1



0.1 0.2
0.2







0.1
Total 0.1 0.2 0.0 0.0 0.2 0.1 5.6 3.9 2.8 4.4 5.3 3.6 0.0 0.1 0.1 0.1 0.3 0.2 0.0 0.4 0.1 0.0 0.2 0.0 0.0 0.1 0.2 0.3 0.1 0.0

Applicant's summary and conclusion

Conclusions:
It is concluded that under the conditions of this experiment, no evidence of mutagenic effects was obtained in Chinese hamsters treated with the test substance.