Normal rat liver hepatocytes and the hepatocytes of hepatic nodules induced by N-2-fluorenylacetamide respond to 70% hepatectomy with vigorous mitotic activity. The administration of L-asparaginase at the time of operation

Normal rat liver hepatocytes and the hepatocytes of hepatic nodules induced by N-2-fluorenylacetamide respond to 70% hepatectomy with vigorous mitotic activity. The administration of L-asparaginase at the time of operation delays the mitotic cycle of every normal hepatocyte by 10 to 12 hr. When L-asparaginase was administered to rats which had received N-2-fluorenylacetamide, an 80% inhibition of mitotic activity of the hepatocytes of the nodules occurred. However, aggregates of cells resistant to the effect of the enzymes were noted in a number of nodules. These resistant cells represent a metabolic subpopulation within the hyperplastic nodule.