Effects Of Different Reperfusion Sequences On Hepatic Ischemia-reperfusion Injury

Objective To investigate the effects of different reperfusion sequences on hepatic warm ischemia-reperfusion injury and the related mechanisms.Methods Ninety-six healthy male Sprague Dawley rats were randomly divided into 6 groups by the random digits method(n=16,each):Sham operation group, only sham operated for negative control; the other 5 groups were all experimental groups, which were divided according to different reperfusion sequences of portal vein and hepatic artery : reperfusion first through the portal vein for 1 min with subsequent full reperfusion group, reperfusion first through the portal vein for 2 min with subsequent full reperfusion group, reperfusion first through the hepatic artery for 1 min with subsequent full reperfusion group, reperfusion first through the hepatic artery for 2 min with subsequent full reperfusion group, simultaneous reperfusion through the portal vein and hepatic artery group. Each group was further randomly divided into two sub groups(n=8,each) for sample collection at 2,4 hours after reperfusion respectively. Serum alanine aminotransferase (ALT), aspartate aminotransferase (AST) and malondialdehyde (MDA), superoxide dismutase (SOD), glutathion (GSH) in hepatic tissue were detected respectively. HE staining was used to observe the morphological changes of hepatic structure. TUNEL method was used to assess the apoptosis index (AI) of hepatocytes.Results The liver of rats was mainly normal in the sham operation group with lower levels of ALT,AST, MDA, AI and higher levels of SOD,GSH compared with all the experimental groups (P<0.01). Less hepatic ischemia-reperfusion injury was found in reperfusion first through the portal vein for 1 min with subsequent full reperfusion group, whose ALT, AST, MDA and AI levels were significantly lower than those of the other experimental groups (P<0.05 or P<0.01), and its SOD, GSH levels were higher than those of the other experimental groups (P<0.05 or P<0.01). HE staining also showed milder hepatic injury in reperfusion first through the portal vein for 1 min with subsequent full reperfusion group than that of the other experimental groups.Conclusions Hepatic reperfusion first through the portal vein for short time could depress the synthesis of free oxygen radicals and suppress apoptosis of hepatocyte, thus relieving hepatic ischemia-reperfusion injury.