EFFECTS OF BILIARY OBSTRUCTION ON THE ENDOCYTIC ACTIVITY IN HEPATOCYTE AND LIVER SINUSOIDAL ENDOTHELIAL-CELLS IN RATS

Obstructive jaundice impairs function in liver parenchymal and sinusoi dal cells. In this study, the endocytic activity in sinusoidal endothe lial cells in the rats with biliary obstruction was measured by plasma clearance of radiolabeled formaldehyde-treated bovine serum albumin. The endocytic activity in hepatocytes was also measured with asialofet uin. The clearance of asialofetuin significantly decreased after 1 wee k of biliary obstruction and the clearance was reduced to 42% of the c ontrols at 4 weeks. In contrast, the clearance of formaldehyde-treated bovine serum albumin was essentially unchanged until 4 weeks of bilia ry obstruction. The maximal removal rate which was assessed by kinetic analysis of injected protein for formaldehyde-treated bovine serum al bumin showed no significant decrease at 2 weeks compared with the cont rols, while that for asialofetuin was significantly decreased to 50% o f the controls, These results suggest that the endocytosis of formalde hyde-treated bovine serum albumin in endothelial cells is maintained u ntil the advanced stage of biliary obstruction, whereas the endocytic activity for asialofetuin in hepatocytes is impaired earlier.