Pleomorphism of hepatic regeneration.

The pleomorphism of hepatic regeneration was studied in acute liver injury and partial hepatectomy of rats. Increases in 3H-thymidine incorporation into the liver DNA fraction and in liver ornithine decarboxylase (ODC) activity were observed similarly in acute liver injury and following a two-thirds partial hepatectomy in normal rats. However, the increase in serum AFP levels was significant only in carbon tetrachloride (CCl4)-treated rats, and the portal-peripheral vein difference in plasma glucagon concentrations was great only in rats that underwent a partial hepatectomy. The weight of the remaining liver increased rapidly following a 67% hepatectomy in normal rats, but not in cirrhotic rats, of which three of five died within 6 days. Increases in liver prostaglandin E levels, 14C-orotate incorporation into the liver RNA fraction and hepatic ODC activity were observed up to 10 h following a partial hepatectomy of normal liver but not after similar removal of cirrhotic liver. Three kinds of hepatic regeneration, i.e., normal and pathologic regeneration following surgical removal of either normal or injured liver and repair of liver damage following chemically induced liver deficiency, were proposed from the observations.