Apoptosis and proliferation of intrahepatic bile duct after ischemia-reperfusion injury.

BACKGROUND: In orthotopic liver transplantation, ischemic-reperfusion is one of the most important factors that cause the incidence of biliary compliance. The aim of this study was to investigate the effects of ischemia reperfusion on epithelial cells apoptosis and proliferation of intrahepatic bile duct (IBD) (>20 microm).
METHODS: 30-minute warm ischemia was applied to rat livers respectively, and experiment was performed on days 2, 7, 14, 28 after reperfusion. Apoptosis was determined in situ by morphology and TUNEL, and cholangiocyte proliferation was evaluated in situ by morphometry of liver sections stained for cytokeratin-19 (CK-19) and by proliferating cellular nuclear antigen staining in liver sections.
RESULTS: Two days after ischemia reperfusion, apoptosis of cells was observed in large intrahepatic bile ducts (>20 microm) (5.6%+/-1.2%), but the number of large intrahepatic bile ducts reduced (0.32+/-0.06). Seven days after ischemia reperfusion, the apoptosis index of cholangiocytes decreased to 1.2%+/-0.3%, and the number of intrahepatic bile ducts began to proliferate and returned to nearly normal on day 28.
CONCLUSION: Ischemia reperfusion causes a decrease in the number of intrahepatic bile ducts (>20 microm) as a result of a higher rate of apoptosis and absence of initial proliferation.