Localization of Alkaline Phosphatase and Cathepsin D during Cell Restoration after Colchicine Treatment in Primary Cultures of Fetal Rat Hepatocytes

Localization of alkaline phosphatase (ALP) and cathepsin D (CAPD) in primary cultures of fetal rat hepatocytes was examined using double immunofluorescent staining in order to investigate the relationship between lysosome movement and the fate of ALP during cell restoration after microtubule disruption by colchicine. At 3 hr and 24 hr after colchicine treatment, numerous coarse dots containing ALP were observed throughout the cytoplasm, and some of these showed colocalization with CAPD. At 48 hr and 72 hr after colchicine treatment, although most of the dots containing ALP in the cytoplasm disappeared, dots containing CAPD remained. The present results suggest that the denatured ALP proteins remaining in the cytoplasm of hepatocytes during cell restoration after colchicine treatment are digested by lysosomes.