MITOTIC INDEX AND LYMPHOCYTE-PROLIFERATION KINETICS IN TESTING THE GENOTOXICITY OF CHEMICAL-AGENTS

The mitotic (MI) and proliferation (PI) indices were investigated to d etermine the effect of N-nitrosodimethylamine (NDMA) in cultured blood lymphocytes of cows, pigs, and sheep. Our results confirmed the abili ty of all animal lymphocytes to metabolize this chemical agent to muta genic products. Treatment with NDMA caused inhibition of MI and PI whi ch were more expressive in bovine lymphocytes. In addition, statistica lly significant heterogeneity of the first, second, and third metaphas es between the treated and untreated cultures was found. Mean PI value s were used to estimate cell-cycle delays showing the highest effect i n bovine lymphocytes.