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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
Reliability:
2 (reliable with restrictions)
Rationale for reliability incl. deficiencies:
other: Secondary literature source
Cross-referenceopen allclose all
Reason / purpose:
reference to same study
Reason / purpose:
reference to other study

Data source

Reference
Reference Type:
publication
Title:
Micronucleated erythrocyte frequency in peripheral blood of B6C3F(1) mice from short-term, prechronic, and chronic studies of the NTP carcinogenesis bioassay program.
Author:
Witt, K.L., Knapton, A., Wehr, C.M., Hook, G.J., Mirsalis J., Shelby M.D., MacGregor J.T.
Year:
2000
Bibliographic source:
Environ Mol Mutagen. 2000;36(3):163-94.

Materials and methods

Test guideline
Qualifier:
no guideline followed
Principles of method if other than guideline:
Data presented in this study sre for studies not previously published.
GLP compliance:
not specified
Type of assay:
micronucleus assay

Test material

Reference
Name:
Unnamed
Type:
Constituent
Details on test material:
No information provided

Test animals

Species:
mouse
Strain:
B6C3F1
Sex:
not specified
Details on test animals and environmental conditions:
No information provided

Administration / exposure

Route of administration:
other: no data
Vehicle:
No information provided
Details on exposure:
No information provided
Duration of treatment / exposure:
No information provided
Frequency of treatment:
No information provided
Post exposure period:
No information provided
Doses / concentrations
Remarks:
Doses / Concentrations:
Concentration range not specified
Basis:
no data
No. of animals per sex per dose:
No information provided
Control animals:
not specified
Positive control(s):
no data

Examinations

Tissues and cell types examined:
Bone marrow and erythrocytes
Details of tissue and slide preparation:
No information provided
Evaluation criteria:
No information provided
Statistics:
No information provided

Results and discussion

Test results
Sex:
not specified
Genotoxicity:
not specified
Toxicity:
not specified
Vehicle controls validity:
not specified
Negative controls validity:
not specified
Positive controls validity:
not specified
Additional information on results:
Results indicate that the test has low sensitivity for prediction of carcinogenicity, a convincingly positive result in this assay appears to be highly predictive of rodent carcinogenicity.

Any other information on results incl. tables

No additional information

Applicant's summary and conclusion

Conclusions:
Interpretation of results (migrated information): positive
The results indicate that the test has low sensitivity for prediction of carcinogenicity, a convincingly positive result in this assay appears to be highly predictive of rodent carcinogenicity.
Executive summary:

In a study conducted by Witt et al (2000) the mouse peripheral blood micronucleus (MN) test was performed on samples collected from 20 short-term, 67 sub-chronic and 5 chronic toxicity and carcinogenicity studies conducted by the National Toxicology Program (NTP). Data in this resport are presented for studies not previously published. The incidence on MN-PCE provided an index of damage induced within 72 hours of sampling whereas the incidence of MN in the NCE population at steady state provided an index of the average damage during the 30 -day period preceding sampling.

Data derived from peripheral blood MN analyses of dosed animals provided a useful indication of the in vivo potential for induced genetic damage and supply an important piece of evidence to be considered in the overall assessment of toxicity and health risk of a particular chemical. Although results indicated that the test has low sensitivity for prediction of carcinogenicity, a convincingly positive result in this assay appears to be highly predictive of rodent carcinogenicity.