Registration Dossier

Administrative data

Endpoint:
in vivo mammalian somatic cell study: cytogenicity / erythrocyte micronucleus
Remarks:
Type of genotoxicity: gene mutation
Type of information:
experimental study
Adequacy of study:
key study
Reliability:
1 (reliable without restriction)

Data source

Reference
Reference Type:
study report
Title:
Unnamed
Year:
2011

Materials and methods

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

Test material

Reference
Name:
Unnamed
Type:
Constituent
Test material form:
solid: flakes
Details on test material:
the test material was suspended in propylene glycol. the formulations were prepared within 4 hours prior to dosing. Homogeneity was accomplished to a visually acceptable level.

Test animals

Species:
mouse
Strain:
NMRI
Sex:
male
Details on test animals and environmental conditions:
Controlled environment, with 15 air change/hour, a temperature of 21°C +/-3°C, a relative humidity of 40-70% and a 12 hour light/12 hours dark cycle.
Animals were group housed (5 animals per sex par cage), they had free access to tap-water and to pelleted rodent diet.
Analysis of bedding, paper, diet and water did not reveal any findings that were considered to have affected study integrity.

Administration / exposure

Route of administration:
oral: gavage
Vehicle:

- Vehicle(s)/solvent(s) used: propylene glycol
Details on exposure:
PREPARATION OF DOSING SOLUTIONS:

the formulations (w/w) were prepared within 4 hours prior to dosing.
Duration of treatment / exposure:
DOSE RANGE FINDING STUDY :
seven dose groups, comprising of 1 to 3 male and female animals, received a dose of tetrahydrocyclopenta[c]pyrrole-1,3(2H,3aH)-dione.
the observation period after dosing was 1 to 3 days.

MAIN STUDY :
Since there were no substancial differencies in toxicity between sexes, only male animals were used in the main study.
The dosing volume was 5 ml/kg bodyweight.
Three dose levels used at the first sampling time, which occured 24 h after treatment.
Only one (the highest) at the second sampling time, which occured 48 h after treatment.
Doses / concentrationsopen allclose all
Remarks:
Doses / Concentrations:
875 mg/kg bodyweight
Basis:
actual ingested
Remarks:
Doses / Concentrations:
440 mg/kg bodyweight
Basis:
actual ingested
Remarks:
Doses / Concentrations:
220 mg/kg bodyweight
Basis:
actual ingested
No. of animals per sex per dose:
five male
Positive control(s):
cyclophosphamide

- Route of administration: single oral intubation
- Doses / concentrations: concentration of 40 mg/kg bodyweight
- Volume : 10 ml/kg bodyweight.

Examinations

Tissues and cell types examined:
Bone marrow
Details of tissue and slide preparation:
ISOLATION OF BONE MARROW :

Both femurs of each animals were removed and freed of blood and muscles.
Both ends of the bone were shortened until a small opening to the marrow canal becale visible.
The bone was flushed with approx. 2 ml of fetal calf serum. The cell suspension was collected and centrifuged at 1000 rpm for 5 min.

PREPARATION OF THE SLIDES :
two slides prepared per animal.
slides prepared with ethanol and cleaned.
the preparations were air-dried, fixed for 5 min in 100% methanol and air-dried overnight.

Electronic data capture : REES centron environmental monitoring system version SQL 2.0 program.
Evaluation criteria:
test substance considered as positive in the micronucleus test if it induces a biologically as well as a statistically significant increase in the incidence of micronucleated polychromatic erythrocytes (at any dose or at any sampling time) and the number of micronucleated polychromatic erythrocytes are above the historical control data range

Results and discussion

Applicant's summary and conclusion

Conclusions:
Interpretation of results (migrated information): negative