Differentiation by colchicine and vincristine sulphate of regenerative hepatocellular mitosis and tumour-associated hepatocellular mitosis.

Colchicine and vincristine sulphate differentiate sharply between hepatocyte mitosis associated with the Ehrlich ascites tumour, and regenerative (post-CCl4 necrosis) hepatocyte mitosis. In the former case there is a gross depression of prophase index and a marked lowering of the overall mitotic index. In the latter, although a degree of prophase depression is evident, this is insufficient to prevent an overall substantial elevation of mitotic index due to accumulation at metaphase. Very low doses of colchicine claimed to be effective in stathmokinesis of hepatocytes under influence of hepatomitogenic tumour brei and tumour extracts, produced no discernible effect on the mitotic pattern of hepatocytes in Ehrlich ascites tumour-bearing mice nor in post-CCl4 regenerating livers. The results are discussed in the context of known features of tumour-associated hepatocellular mitosis.