Mntbap Protective Effect Of Small-size Liver Graft Ischemia-reperfusion Injury

PartⅠDifferent methods to establish rat small-for-size liver transplantation model bycomparisonObjective:to explore an effective and viable way to establish small-for-size livertransplantation model in the rat by single person on the basis of skilled grasp of thesmall-for-size liver transplantation model.Methods:Male SD rats are randomly divided into the following groups as donors andrecipients:Group A:According to Miyata M,15 rats for to establish 30% size graft livertransplantation using a median lobe graft by"three-cuff"techniques;Group B(n=15):30% sizegraft liver transplantation rat model using a median lobe graft by Kamada's"two-cuff method"on the basis of skilled grasp of the small-for-size liver transplantation model;Time for surgicalprocedure including duration of donor-graft preparation,recipient operation and anhepaticphase,7-day survival rate and the technical complications are compared between the twogroups.Results:Compared to Group B,the times for donor-graft preparation,recipient operationin Group A is longer (P＜0.05) ,the mean times to perform SHVC anastomoses and anhepaticphase is less (P＜0.05) but higher in failure rate to complishment of the connection (P＞0.05).Compared Group B,Surgical complications in group A show no significant difference(P＞0.05) .There are no significant differences in the 7-day survival rate between twotransplantation groups (P＞0.05) ,though Group B has more survivors 7 days after livertransplantation.Conclusion:With improved method of cuff connection,more effective and viable 30%small-for-size rat liver transplantation model with two-cuff method can be established stablly. PartⅡProtective effects of MnTBAP on small graft for size of liver transplantation afterischemia reperfusion injury in ratsObjective:To observe the protective effects of MnTBAP on small graft for size of livertransplantation after ischemia reperfusion (I/R) injury in rats and to find out its possiblemechanism.Methods:Male SD rats are randomly divided into three groups,which were shamoperation group,untreated group and MnTBAP treated group,and both untreated group andMnTBAP treated group contain different size graft animals including 60%LDLT,45%LDLTand 30%LDLT.Alanine aminotransferase (ALT) in rats after 3h,6h,12h,24h and 48h afterreperfusion are evaluated,and the activity of superoxide dismutase (SOD) and the content ofmalondialdehyde (MDA) in ischemia small graft for size are examined.The apoptotic index(AI) of hepatocytes in small graft for size is detected by terminal deoxyribonucleo -tidyltransferase (TdT)mediated dUTPbiotin nick end labeling (TUNEL) methods.The expressionof TNF-a and NF-κB are examined by ELISA methods.Results:Even though the pressure of portal vein has no difference between untreatedgroup and MnTBAP treated group(P＞0.05),But serum ALT in rats after 3h,6h,12h,24h,48hafter reperfusion in MnTBAP treated group are obviously lower as compared with those in theuntreated group (P＜0.01),and MDA in MnTBAP treated group are lower VS.those in theuntreated group (P＜0.05);The decreased apoptotic index and the expression ofdownregulated TNF-a and NF-κB are also observed in MnTBAP treated group in 6h,12h,24hand 48h after reperfusion(P＜0.05).In untreated group,the expression of TNF-a is highestamong the three groups(P＜0.05),and the serum ALT(P＜0.01) and MDA level is highesttoo(P＜0.05).The hepatocellular apoptosis is more serious than that in other groups(P＜0.05).Conclusion:The protective effects of MnTBAP against I/R injury of small graft for sizemay associate with highly scavenging reactive oxygen species(ROS),reducing lipidperoxidation injury and inhibiting apoptosis.which may due to the smaller graft size,refusionwith higher portal pressure,and subsequent hepatic parenchymal injury. PartⅢEffect on Liver Regeneration of Small for Size Graft in Liver Transplantation RatsAdministered MnTBAPObjective:To study the protective effect and the possible mechanism on liverregeneration of small for size graft in liver transplantation rat models administered MnTBAPvia peritoneal cavity.Methods:Male Sprague-Dawley rats are divided into six groups for three groups(n = 30in each group)of liver transplantation models with graft volume / standard liver volumerespectively 60%,45 % and 30% which are untreated group by MnTBAP ;Other three groups(n= 30 in each group)of liver transplantation models with the same graft volume / standard livervolume which are treated by MnTBAP group.The expression of TNF-α,IL-6,Stat3/Pstat3,JNK and the level of malondialdehyde(MDA) are detected as well as alanineaminotransferase(ALT) level at 3,6,12,24h and 48h after reperfusion.Proliferating CellNuclear Antigen (PCNA) is detected by immunohistochemical methods.The morphologicalchanges of hepatic tissue were observed through light microscope at different time points.Result:Compared with the same volume graft of untreated group,That the graftexpress TNF-αand the level of IL-6 are significantly lower (P＜0.05) in all treated groups byMnTBAP and these animals exhibit improved liver function and liver weight recovery duringthe early post-transplantation.In liver transplantation model groups treated by MnTBAPexcept 30% with graft volume / standard liver volume,the graft express JNK and Pstat3 andare no significantly differance in 6,12,24h after refusion than that in untreatedgroup(P＞0.05),meanwhile compared with the same volume graft of untreated group,thepercentage of PCNA is almost at the same level in all groups except that in 30% livertransplantation untreated group(P＜0.05).Conclusion:MnTBAP can decrease the activities of ROS and the release ofinflammatory mediators to protect the graft against ischemia / reperfusion injury but canfurther mantain JNK activation by highly durative expression of IL-6 and TNF-α.It may offera novel approach to protect liver regeneration after small-for-size-graft transplantation.