Development of the optimal dose of cytochalasine B in the MN assay in a domestic cat

Cytochalasine B is an indicator in the CBMN assay, but can also be geno- or cytotoxic. The aim of the study was to determine the optimal dose of cytochalasine B for the Cytokinesis-Block Micronucleus (CBMN) assay for the domestic cat. The results revealed a surprisingly high number of micronuclei (MN) in relation to the doses used. It was found that a concentration of 2.5 μg/ml is enough to obtain binuclear cells, with a minimal toxic effect on the lymphocytes of the domestic cat. In the material analysed, three forms of chromatin structure abnormalities were found. The most prevalent abnormalities were isolated micronuclei, with the mean number of binucleated cells with one micronucleus (BNCs + 1 MN) equal to 39.96 ± 9.02. Moreover, the numbers of binucleated cells with one micronucleus, nuclear buds and nucleoplasmic bridges did not differ significantly according to the sex or age of European cats.