Abstract
In order to clarify the growth mechanisms of normal hepatocytes, the kinetics of hepatocellular regeneration after 70% hepatectomy and after hepatic injury induced by Dgalactosamine was studied.
The liver parenchyma of adult animals is mixed population of cells with differing DNA content. Cytofluorometric analysis revealed that DNA histograms of normal rat liver cells had two peaks in 2c (41%) and 4c (51%) of relative DNA content, and that these cells were arrested in the G0 or G1 phases of the cell cycle. A surgical removal of 70% of the liver in rats induced polyploidization of the hepatocytes, but only slight polyploidization was observed during regeneration after an administration of 1g/kg·bw D-galactosamine. Chromosomal analyses of regenerated livers showed that no hepatocyte had diplochromosomes, thus revealing that the polyploidization of hepatocytes was not due to endoreduplication.
Moreover, a comparison between the regeneration of the remaining cells after partial hepatectomy and those after D-galactosamine hepatic injury suggests that the growth kinetics of hepatocytes differs depending on the type, grade and strength of stimulation, and that the somatic and focal regulatory mechanisms function in the growth of hepatocytes.
