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Objective To investigate the expression of hypoxia inducible factor-1α(HIF-1α)in the transplanted liver in rats and the role of HIF-1α in the JNK signaling pathway.Methods Ninety-six SD rats were randomly divided into normal control(NC)group,autotransplantation(AT)group,hypoxia preconditioning (HP)+ AT group according to simple random sampling method.No treatment was applied to the rats in the NC group except for blood vessel separation.Stable rat models of 70％ AT was established in the AT group.Rats in the HP + AT group were given 8％ oxygen mixed gas for 90 minutes before the operation.The levels of alanine aminotransferase(ALT)and aspartate aminotransferase(AST)were detected at 1,2,12,24 hours after operation,and the expression of HIF-1α in the hepatic tissue,mRNA expression of c-Jun,and protein expression of Cleaved Caspase-3 were detected by immunohistochemical staining,reverse transcription-polymerase chain reaction and Western blot,respectively.All data were analyzed using the analysis of variance or t test.Results The levels of ALT and AST in the HP + AT group were significantly lower than those in the AT group,while higher than those in the NC group at 1,2,12 and 24 hours after the operation(F=2631.371,1177.642,810.383,682.848;743.618,1095.522,375.995,580.613,P ＜0.05).The protein expression levels of HIF-1α in the AT group were significantly lower than those in the HP + AT group,but higher than those in the NC group at 1,2,12 and 24 hours after operation(F = 191.737,284.482,459.419,213.782,P ＜ 0.05).The mRNA expression levels of c-Jun in the HP + AT group were significantly lower than those in the AT group,while higher than those in the NC group at 1,2 and 12 hours after operation(F = 66.211,53.169,9.645,P ＜ 0.05).There was no significant difference in the mRNA expression of c-Jun among the 3 groups at 24 hours after operation(F = 1.100,P ＞ 0.05).The protein expressions of Cleaved Caspase-3 in the HP + AT group were significantly lower than those in the AT group,while higher than those in the NC group at 1,2,12 and 24 hours after the operation(F =23.133,31.158,14.347,29.043,P ＜ 0.05).Conclusion High expression of HIF-1α after HP inhibits apoptosis of hepatic cells and alleviates ischemia reperfusion injury of hepatic tissues by suppressing JNK activation,down-regulating protein expression of Cleaved Caspase-3 after orthotopic liver transplantation in rats.
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Objective To investigate the effect of hypoxic preconditioning on hepatocytes early growth response factor 1 ( EGR-1 ) in a rat liver autotransplantation. Methods The rat portal vein perfusion model was established for donor liver autotransplantation. Rats were then divided into group A:hypoxic preconditioning was done before transplantation; group B: rats undergoing liver transplantation without preconditioning; group C: Normal control group of rats. Liver histopathological changes, the mRNA expression of HIF-1, TNF-1 and the WB results of EGR-1 were compared between groups. Results The expression of HIF-1 α RNA determined in group A was more obvious than in group B and group C. Six hours after surgery, the expression in group A was significantly higher than that in group B (t =9. 601, df= 10, 2-tailed Sig = 0. 000, P<0. 05 ) ; Egr-1 protein expression in group A and group B increased after surgery,with that in group A being significantly lower than that in group B. The RT-PCR expression of TNF-α RNA in group B compared with group A and group C was more obvious. Six hours after operation, the expression of TNF in group B was significantly higher than that in group A ( t = -12. 067, df = 10, 2-tailed Sig =0. 000, P<0. 05 ). The expression of Egr-1 was positively correlated with that of TNF. A liver cell pathology showed less severe injury in structure of hepatic lobule, mild swelling of liver cells, no significant changes in liver tissue. Conclusions Hypoxic preconditioning adaptation in rat liver transplantation generates modest increase in EGR-1, and reduces the production of TNF and other inflammatory factors.
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Objective To investigate the change of the mitochondrial aspartate aminotransferase (mAST), and the ratio of m-AST and aspartate aminotransferase (AST) in rat orthotopic liver transplantation.Methods We used the rat autologous orthotopic liver transplantation modelin which liver was infused by portal vein. Group A: Autologous orthotopic liver transplantation. Group B: Sham control group of normal rats. To measure the m-AST, AST and ALT in rat serum at each time, the ratio of m-AST/AST was calculated to observe the changes after surgery. Results The ALT of group A after 1 h was 1149.2 U/L, while the ALT of group B was 111.3 U/L; The AST of group A ofter 1 h was 819.5 U/L, while the AST of group B was 128.2 U/L; The m-AST of group After 1 h was 290.8 U/L, while the m-AST of group B was 40.5 U/L. The levels of m-AST, AST and ALT in group A were significantly higher than group B (P ＜ 0. 05).Group A significantly increased the degree of liver damage compared with group B. The ratio of m-AST/AST in group A changed with time obviously. Because the haff-life of m-AST in serum was shorter than that of AST, and AST in this study returned to normal slowly, the ratio of m- AST/AST in A group decreased after 6 h and the number is 0. 12. It indicating that the damage of mitochondria in rat liver cells has been restored after 6h. Conclusions It will be better to judge the prognosis of liver transplantation from the changes of serum m-AST in rats. And it seems earlier to reflect the injury or recovery of liver cell compared with AST.It also has the guiding values to diagnose and treat the damage of liver cells and mitochondrial in the rat liver transplantation.