Role of liver functions on liver cell mitosis

The control mechanism of mitosis in the regenerating rat liver was studied in relation to the cell functions. Partial hepatec· tomy induces a series of changes prior to the initiation of mitosis, i. e. decrease in serum glucose and albumin levels, loss of glycogen from liver cells, and increased lipid mobilization to liver cells. Massive supplies of glucose and fructose suppressed significantly hepatocellu. lar mitosis with suppression of lipid accumulation and preservation of glycogen in the liver cells and of blood sugar level. Homologous serum administration also suppressed the rate of liver cell mitosis after hepatectomy preventing the decrease in serum albumin level, but did not suppress the lipid accumulation in the liver. Starvation, which would relieve the liver cell from the work of detoxication of intesti. nal toxic products, did not show any suppressive effect on the mitotic rate of liver cells after partial hepatectomy in single animals. But starvation induced severe hypoglycemia, moderate hypoalbuminemia and loss of glycogen content in the liver. These changes in metabo. lism by starvation and partial hepatectomy were suppressed by con· jugating the animals with nonhepatectomized fed.partners by aortic anastomosis, and mitosis was suppressed in the residual liver of the fasting animals in this parabiosis. The results indicate that all the major functions of parenchymal live cells tested, sugar metabolism, serum albumin production, and detoxication, are closely related to the control of liver cell mitosis. Accumulation of lipids in the liver remnant after partial hepatectomy is thought to be for the compensa. tion of reduced glycogen storage and not concerned directly with the liver cell mitosis. Discussion was made briefly on the humoral factor and portal blood factor in relation to excess load of functions on resi. dual liver cells.