Résumé
Objective To investigate theeffect of ischemic postconditioning (IPO) on ischemia/reperfusion injury via mitochondrial pathway.Methods Male Sprague-Dawley rats were divided into three groups by means of random number table.Rats in IRI group and IPO group received liver transplantation.The portal vein in IRI group was opened immediately after liver implantation to restore the blood supply.The graft rats in IPO group received IPO before the portal vein was completely opened: 60-s ischemia and 60-s reperfusion of the portal vein,repeated 6 times).The rats in the sham-operation group were only subject to dissociation of the liver ligament.Six h after portal vein reperfusion,liver function was tested.The expression of Bcl-2 mRNA and Bax mRNA was detected by using real time-PCR.The protein expression of Cyt-c was detected by using Western blotting.The apoptosis and necrosis of liver tissue and the mitochondrial transmembrane potential were detected by using flow cytomertry.The changes of mitochondrial structure were observed under an electron microscope.Results The liver functions in IRI group and IPO group were significantly worse (P＜0.05),the levels of Bax mRNA were significantly higher (P＜0.05),the levels of Bcl-2 mRNA were significantly lower (P＜0.05),the levels of Cyt-c protein were significantly higher (P＜0.05),the levels of apoptosis and necrosis were significantly higher (P＜0.05),and mitochondrial transmembrane potential (MTP) of liver cells was significantly lower (P＜0.05) than in sham operation group.The changes of all the parameters in IRI group were more significant than in IPO group (P ＜ 0.05).The morphological changes of the liver mitochondria were also significantly aggravated in IRI group as compared with IPO group.Conclusion IPO reduced IRI by inhibiting the mitochondrial signaling pathway in rats undergoing liver transplantation.