Enzyme cytochemical study of alkaline phosphatase in rat hepatocytes--change of location after colchicine administration or bile duct ligation.

Changes in location of alkaline phosphatase (ALP) in rat hepatocytes after two different treatments were examined by the enzyme cytochemical technique. Although reaction deposits which indicate ALP activity were observed mainly in the bile canalicular membranes until 6 hr after colchicine administration, they were present not only in the bile canalicular membranes but also in the sinusoidal and lateral membranes 12 hr after drug administration. Eighteen and 24 hr after colchicine administration, a large number of reaction deposits were seen in the sinusoidal membranes and in the mutual membranes between adjacent hepatocytes, where the bile canaliculi were completely deformed and complex interdigitations appeared. On the other hand, after bile duct ligation, reaction deposits appeared in every domain of the plasma membranes. Twenty-four hr after colchicine administration to bile-duct-ligated rats, an increase in the number of the reaction deposits was observed, but the location of ALP remained unchanged. The present study suggests that intracellular transport and location of ALP in hepatocytes may be controlled by a common mechanism in colchicine-treated and bile-duct-ligated rats.