Tauroursodeoxycholic acid protects cholestasis in rat reperfused livers: its roles in hepatic calcium mobilization.

Tauroursodeoxycholic acid (TUDCA) is of potential benefit in cholestatic disorders. However, the effect of TUDCA on hepatic ischemia-reperfusion injury is unknown. We studied this subject with particular regard to its roles in hepatic calcium mobilization. Three doses of TUDCA were used with continuous intravenous infusion (1.0, 0.1, and 0.01 micromol/kg body weight/min). At 3 hr after 1 hr of ischemia and reperfusion in 70% rat liver, high-dose TUDCA reduced hepatic reperfused injury according to biochemical and histological findings and significantly increased bile flow after reperfusion. It significantly increased tissue calcium content and serum calcium concentration after reperfusion. Furthermore, it also enhanced biliary calcium concentration and total output during reperfusion. In conclusion, TUDCA has a salutary effect on ischemia-reperfusion injury of the liver. However, it is still unclear how the calcium mobilization induced by TUDCA is associated with the hepatoprotection against ischemia-reperfusion injury.