Experimental research of ischemic preconditioning on the protective effect of the recipient after liver transplantation in rats

Objective:To observe the effect of ischemic preconditioning(IP) on C-X-C chemokine expression and PMNs infiltration in the early stage after liver transplantation to explore the mechanism of protective function.Methods:Male Sprange-Dawley rats were used as donors and recipients of orthotopic liver transplantation(OLT). The donor liver was stored for 24 hours in University of Wisconsin(UW) solution at 4 ℃ before implantation. All rats were randomly divided into two groups:non-IP group and IP group. The portal vein and hepatic artery of the donor liver were clamped for 10 minutes in IP group followed by reperfusion for 10 minutes before liver was cut and taken out. The intrahepatic activity of myeloperoxidase(MPO),serum hepatic enzymology indecis,serum levels of macrophage inflammatory protein-2(MIP) and tumor necrosis factor(TNF)-α were separately assayed after 1 h,2 h,4 h and 6 h after liver transplantation. The hepatic tissues after 4 hours postoperatively were examined routinely.Results:Alterations of the hepatic enzymology indecis suggested that the hepatic function was improved effectively in IP group. Levels of MPO in IP group at each time were lowered than that in non-IP group. And at 4 h(0.48±0.18 U/gm tissue and 0.85±0.11 U/gm tissue) and 6 h(0.63±0.04/gm tissue and 0.77±0.55/gm tissue),the decreases were significant. Similarly,serum MIP-2 was significantly reduced in IP group versus non-IP group(2546.59±707.78 pg/ml and 3488.82±785.15 pg/ml at 4 h,1023.72±656.86 pg/ml and 1852.04±1108.89 pg/ml at 6 h). Changes of serum TNF-α was significant only at 2 h after transplantation(370.77±146.82 pg/ml and 517.41±57.30 pg/ml).Conclusion:This study indicates that IP may protect graft liver from preservation-reperfusion injury after OLT through down-regulation C-X-C chemokine expression of hepatocytes,which alleviates PMNs infiltration after transplantatin.