Comparative Studies of the Protective Effects of Ischemic Posconditioning and Preconditioning on Rat Liver

Objective To compare the protective effects of ischemic postconditioning and preconditioning on female rat liver. Methods With rat models of acute liver ischemia-repeffusion,24 healthy female Wister were randomly divided into sham-opera- ted,ischemia-reperfusion(IR),ischemic preconditioning(IPC)and ischemic postconditioning(IPo)groups.IPC was achieved by brief episodes of ischemia/reperfusion applied prior to ischemia,while IPo was achieved by a series of brief interruptions of reperfusion at the very onset of reperfusion.Then we observed the quantity change of SOD,MDA,NO and NOS in hepatic tissue after 24h and ex- amined it pathologically.Results Compared with 1R,the activity of plasma enzyme and the concentrations of malondialdehyde (MDA)in hepatictissue in IPC and IPo decreased sharply(P0.01),while the concentrations of superoxide dismutase(SOD)and nitric oxide(NO)and nitric oxide synthase(NOS)increased significantly(P0.01).Moreover,the hepatic tissue patheological damage also relieved obviously.The difference between IPo and IPC was not obvious(P0.05).Conclusions IPo can attenuate hepatic ischemia-reperfusion injury by reducing the superoxide radical generation and increasing the effects of NO.There was no obvi- ous difference between the protective effects of ischemic posconditioning and preconditioning.