[Electron histochemical alteration on the plasma membrane of biliary epithelial cells in obstructive jaundice]

The plasma membrane of rat's biliary epithelial cells were histochemically examined in experimentally induced obstructive jaundice. Ultrastructurally, atrophy of microvilli and bleb formation were observed in bile canaliculi and ductular cells. These morphological alteration and microfilament aggregation were still remained even 2 weeks after the biliary drainage of 2 weeks obstruction. Histochemically, the reaction products of ruthenium red (RR), alkaline phosphatase (ALPase) and Na+ K+ ATPase were localized on the luminal membrane of the ductular cells and bile canaliculi in the control. In the obstructive jaundice, the reaction products of RR and Na+ K+ ATPase were decreased, and ALPase were localized on the sinusoidal, lateral and bile canalicular membranes of hepatocytes. In the biliary drainage after 2 weeks obstruction, the reaction products on the ductular cells were decreased even 2 weeks later. However RR, ALPase and Na+ K+ ATPase were rearranged on the bile canalicular membrane compared with the ductular cell membrane. These findings suggest that the molecular changes of the plasma membrane of biliary epithelial cells in long term obstructive jaundice would be prolonged after the biliary drainage and the membrane vulnerability of the ductular cells would be different from that of the bile canaliculi.