Pyrrolo[3,4-c]pyrrole-1,4-dione, 3,6-bis(4-chlorophenyl)-2,5-dihydro-

Genetic toxicity: in vivo

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:

2 (reliable with restrictions)

Rationale for reliability incl. deficiencies:

other: see 'Remark'

Remarks:

GLP compliance was not stated in the report. The test conduct was in principle similar to the OECD 474 (1981). However, with following deviations: Mice or rats are recommended in the guideline; Chinese hamster were used in this study. Additionally, 1000 polychromatic erythrocytes/animal were scored for the incidence of micronuclei instead of 2000 as claimed in the guideline.

Data source

Reference

Reference Type:

study report

Title:

Unnamed

Year:

1986

Report date:

1986

Materials and methods

Test guideline

Qualifier:

equivalent or similar to guideline

Guideline:

OECD Guideline 474 (Mammalian Erythrocyte Micronucleus Test)

Deviations:

yes

Principles of method if other than guideline:

Mice or rats are recommended in the guideline. Chinese hamster were used in this study. Additionally, 1000 polychromatic erythrocytes/animal were scored for the incidence of micronuclei instead of 2000 claimed in the guideline.

GLP compliance:

no

Remarks:

not stated in the report

Type of assay:

micronucleus assay

Test material

Test material information

Constituent 1

Details on test material:

- Purity: Commercial grade
- Lot/batch No.: Op. 11006
- Stability of test article: In the report it was stated that stability was guaranteed by the sponsor.

Test animals

Species:

hamster, Chinese

Strain:

other: random outbred

Sex:

male/female

Details on test animals or test system and environmental conditions:

TEST ANIMALS
- Strain as stated in the report: Chinese hamster (Cricetulus griseus), random outbred strain
- Source: CIBA-GEIGY LTD. Tierfarm, Sisseln, Switzerland
- Age at study initiation: 6 - 10 weeks (males), 4 - 9 weeks (females)
- Weight at study initiation: 20 - 28 g (females), 23 - 33 g (males)
- Housing: individually
- Diet (ad libitum): standard diet, NAFAG No. 924
- Water (ad libitum): tap water

ENVIRONMENTAL CONDITIONS
- Temperature (°C): 22 - 23
- Humidity (%): 48 - 51
- Photoperiod (hrs dark / hrs light): 12 / 12

Administration / exposure

Route of administration:

oral: gavage

Vehicle:

- Vehicle: 0.5 % aqueous solution of sodium carboxymethylcellulose (CMC)
- Concentration of test material in vehicle: 5000 mg/kg bw in 20 ml/kg bw

Duration of treatment / exposure:

After single oral administration of 5000 mg/kg bw animals were observed for 16, 24 and 48 h.

Frequency of treatment:

Single oral administration.

Post exposure period:

16, 24 and 48 h.

Doses / concentrations

Remarks:

Doses / Concentrations:
5000 mg/kg bw
Basis:
actual ingested

No. of animals per sex per dose:

16 animals (8 females, 8 males).

Control animals:

yes, concurrent no treatment

Positive control(s):

Animals treated with cyclophosphamide (64 mg/kg bw in 20 ml/kg bw 0.5 % CMC) served as positive control.

Examinations

Tissues and cell types examined:

Bone marrow was harvested from the shafts of both femurs. Normochromatic erythrocytes (NCE) as well as polychromatic erythrocytes (PCE) were counted for determination of the PCE/NCE-ratio. 1000 PCE per animal were used to determine the incidence of micronucleated PCE.

Details of tissue and slide preparation:

Bone marrow was harvested from the shafts of both femurs with a pipette and aspirated gently in 0.5 µl rat serum. Small drops of the mixture were transferred on a slide and spread out by pulling it behind a cover glass. The preparations were air-dried and stained in undiluted May-Grünwald solution (2 min) and subsequently in May-Grünwald solution/water 1/1 (2 min), followed by 20 minutes in 40 % Giemsa's. Following rinsing and washing with 55 % methanol and/or water, the slides were air-dried, cleared in Xylene and mounted in Eukitt.

Statistics:

The significance of difference was assessed by Chi square - test.

Results and discussion

Test results

Sex:

male/female

Genotoxicity:

negative

Remarks:

(Micronucleated PCE cells 0.18 % versus 0.13 % in negative control)

Toxicity:

no effects

Remarks:

(No significant difference in PCE/NCE-ratio between treated and negative control)

Vehicle controls validity:

valid

Negative controls validity:

other: see vehicle control

Positive controls validity:

valid

Any other information on results incl. tables

One female animal of the control group died during the experiment.

The percentage of micronucleated PCE was 0.13 % in the negative, 0.18 % in the treated group and 3.34 % in the positive control. As expected the positive control was statistically significantly different from negative control.