The Study On Protection Difference Of Aniso-latitude Ischemia-Preconditioning To Biliary Duct Of IR Rat Liver

Objective: The research focused on ischemic preconditioning whether it can decrease the injury of apoptosis-caused intrahepatic-extrahepatic biliary duct through up-regulation apoptosis repressed gene Bcl-2 and down-regulation apoptosis trigger gene Bax in rat. And the difference of ischemic preconditioning on Bcl-2/Bax among 5-minute and 10-minute latitude were also compared. According to the difference, the best latitude to hepatic and biliary survival after transplantation was also analyzed.Methods: The liver orthotropic ischemic reperfusion mode was established according to Chien CT's methods. 40 SD rats were divided into four groups: SO, IR, IP5, IP10. The blood sample and biliary tissue were harvested after left half liver ischemia-reperfusion. TUNEL technique, hybridization in situ and immunohistochemistry were used to determine apoptotic index and the expression of Bcl-2/Bax mRNA & proteins respectively in 40 biliary specimens. Data were expressed by mean±standard deviation(±s) and t-test and one-factor analysis of variance were used between group comparison and in multi-group comparison respectively. There was statistic significance when P<0.05 in multi-group and between IP group when P<0.10.Results: The model of Group SO,IR,IP were successful. In SO group, apoptosis in biliary duct epithelial cell decreased while in IR group it increased. Compared with IR group, apoptosis in biliary duct epithelial cell was significant (P<0.05). mRNA of biliary duct apoptosis repressed gene Bcl-2 and protein expression are lower in SO group, but high in IR and IP group. IR expression decreased but IP group increased between IR and IP group. Moreover, mRNA and protein expression in IP5 group are a little higher than that in IP10 (P<0.10).In the experiment, we found that the effects in IP5 group were better and were satisfactory. mRNA of apoptosis trigger gene and protein expression is lower(P<0.01) in SO group. However mRNA and protein expressions in biliary duct of apoptosis trigger gene Bax in IR and IP group were not significant(P>0.05). It was concluded that IP could up-regulate apoptosis repressed gene Bcl-2 and act on biliary duct epithelial cell, but the expression of apoptosis trigger gene Bax could not be found simultaneously.Conclusion:1. The biliary duct injury during liver ischemic reperfusion could relate to apoptosis biliary duct epithelial cell.2. Ischemic preconditioning in normal atmospheric temperature could reduce the biliary duct injury in ischemic preconditioning.3. The protective effect of ischemic preconditioning could be achieved through activating up-regulation of Bcl-2 in biliary duct epithelial cell.4. 5minute-ischemic-preconditioning is the best solution for the protection of liver ischemic reperfusion and biliary duct injury.