Different ischemic preconditioning for rat liver graft: protection and mechanism.
OBJECTIVE
To investigate the protective mechanism of different ischemic preconditioning (IPC) to ischemia/reperfusion (I/R) injury of rat liver graft.


METHODS
192 Wistar rats were randomly divided into 4 groups (48 rats in each group): control group (group C), experimental group 1 (group E1), experimental group 2 (group E2), and experimental group 3 (group E3). IPC was not carried out in group C. In the experimental groups, IPC was carried out by blocking blood flow of the portal vein and hepatic artery and then reperfusion by removal of the clamp before donor liver was resected. Group E1: 5-minute ischemia and 10-minute reperfusion; Group E2: 5-minute ischemia and 5-minute reperfusion and one more the same procedure; Group E3: 10-minute ischemia and 15-minute reperfusion. Four hours after IPC, liver transplantations were performed. Recipient blood and graft samples were obtained to determine the levels of ALT, AST, TNF-alpha and apoptosis index at 0.5, 2, 6, 24 hours after portal vein reperfusion.


RESULTS
At 0.5, 2 hours after portal vein reperfusion, the levels of TNF-alpha in the experimental groups E1, E2, and E3 were significantly lower than in the control group (P<0.05), and the levels in group E2 were significantly lower than in groups E1 and E3 (P<0.05). At 24 hours, the levels of TNF-alpha in group E2 were significantly lower than in groups C, E1 and E3 (P<0.05). At 2 and 6 hours, apoptosis index in the experimental groups E1, E2, and E3 was significantly less than in the control group (P<0.05). Apoptosis index in group E2 was significantly less than groups E1 and E3 (P<0.05). At 24 hours apoptosis index in the experimental groups E1, E2, and E3 was significantly less than in the control group (P<0.05).


CONCLUSIONS
Ischemic preconditioning could attenuate liver graft injury by decreasing apoptosis of hepatocytes and production of TNF-alpha. The method of IPC with 5-minute ischemia, 5-minute reperfusion and one more the same procedure is a better way to protect liver graft from ischemia-reperfusion injury.
Zhang
Shui-Jun
SJ
Department of Surgery, First Affiliated Hospital, Zhengzhou University, Zhengzhou 450052, China. zhangshuijun@zzu.edu.cn
Zhu
Chang-Ju
CJ
Zhao
Yong-Fu
YF
Li
Jie
J
Guo
Wen-Zhi
WZ
D000704:Analysis of Variance; D000818:Animals; D001219:Aspartate Aminotransferases / Q000032:analysis; D004195:Disease Models, Animal; D005260:Female; D006084:Graft Rejection; D006085:Graft Survival; D020287:In Situ Nick-End Labeling; D019194:Ischemic Preconditioning / Q000379:methods*; D008099:Liver / Q000098:blood supply*; D008111:Liver Function Tests; D016031:Liver Transplantation / Q000009:adverse effects / Q000379:methods*; D008297:Male; D011336:Probability; D011897:Random Allocation; D051381:Rats; D017208:Rats, Wistar; D015427:Reperfusion Injury / Q000473:pathology / Q000517:prevention & control*; D012680:Sensitivity and Specificity; D014409:Tumor Necrosis Factor-alpha / Q000032:analysis
D014409:Tumor Necrosis Factor-alpha; D001219:Aspartate Aminotransferases