The mutagenic activity of razoxane (ICRF 159): an anticancer agent.

The mutagenic activity of razoxane (ICRF 159) was studied using the Salmonella/microsome assay and rodent bone-marrow micronucleus and metaphase assays. Razoxane (up to 5000 micrograms/plate) did not cause an increase in the mutation frequency in the Salmonella/microsome assay. In the mouse micronucleus assay razoxane (200 and 400 mg kg-1 i.p.) was cytotoxic to the bone marrow cells (which limited the analysis) but an increase in micronucleated polychromatic erythrocytes was observed in razoxane dosed animals (5-fold compared to control value). In the Chinese hamster metaphase assay razoxane (up to 500 mg kg-1 orally) induced abnormal chromosome condensation and an increase in structural chromosome aberrations (7 fold compared to control value) as well as an increase in the number of polypoid cells (8-fold compared to control value). The mutagenic effect of razoxane was restricted to eukaryotic organisms and was associated with specific chromosomal changes.