Histochemical and immunohistochemical study on the expression of alkaline phosphatase, gamma-glutamyl transpeptidase and alpha-fetoprotein during the process of rat hepatocyte proliferation.

The changes in the activity and the localization of alkaline phosphatase (ALP), gamma-glutamyl transpeptidase (gamma-GTP) and alpha-fetoprotein (AFP) were examined during cell regeneration in the galactosamine-injured rat liver. D-galactosamine was injected i.p. into rats at a single dose level of 400 mg/kg. The biochemical activities of ALP and gamma-GTP in rat liver homogenate increased significantly in comparison with those in the control rats 3 days and 4 days after administration of D-galactosamine. In the histochemical analysis, 3 days, 4 days and 5 days after the administration of the amino sugar, a high level of activity of both ALP and gamma-GTP was seen along the cell borders between adjacent hepatocytes. AFP was detected by the enzyme-labeled antibody technique in the cytoplasm of a few small hepatocytes around Glisson's sheath and epithelial cells of small tubules within Glisson's sheath which show morphological features similar to bile duct 3 days, 4 days and 5 days after the administration of the amino sugar. AFP was detected in serum by the western blotting method 3 days and 4 days after the administration of D-galactosamine, whereas serum albumin decreased significantly in the same period. In this study, it was shown that ALP, gamma-GTP and AFP were proper markers to justify the degree of the differentiation of hepatocytes during the state of proliferation.