The Impact Of Ischemic Preconditioning On The Regenerative Capacity Of Hepatocyte In The Preparative Partial Donor Livers

Parâ… Establishment of Animal Model and Study on Ischemic Preconditioning against Ischemia/Reperfusion Injury after Partial Hepatectomy in RatsObjective:To establish the animal models of partial hepatectomy (70%),hepatic ischemia/reperfusion after partial hepatectomy and ischemic preconditioning,to study the effect of ischemic preconditioning on against ischemia/reperfusion injury after partial hepatectomy in rats.Methods:144 Male Sprague Daweley rats were divided into group ischemia/reperfusion(IR),group ischemic preconditioning(IP)and group partial hepatectomy(PH).The group IR rats were subjecyed to segmental liver(30%)ischemia for 30 minute,ischemia liver lobes were then reperfused and non-ischemia liver lobes were resected(70%partial hepatectomy).The group IP rats were pre-treated with ischemic preconditioning(10/10min)before liver lobes(30%)ischemia.The group PH rats were only partial hepatectomy without prior liver ischemia. Specimen was harvested at 0,1,3,6,12,24,48 and 72 hour respectively in three groups rats.Serum ALT and AST were detected by biochemery autoanalyzer,liver tissues were stained with hematoxylinand eosin(HE) for histologic study.Results:(1)In both IR and IP groups,the serum ALT and AST increased gradually with the reperfusion time extending.The peak was at 24 hour after ischemia/reperfusion,then the level decreased lower and lower.(2)Compared with PH group,the level of ALT and AST in group IR were higher significantly at 1h～72h(P＜0.05).(3)Compared with IR group,the level of ALT and AST in group IP were lower significantly at 1h～72h(P＜0.05).(4)Hepatic necrosis and the inflammatory cells infiltration aggravated in IR groups along with the reperfusion.The peak was at 48 hour after ischemia/reperfusion.Compared with IR group,PH group and IP group showed less hepatocyte injury and smaller necrotic area in liver.Conclusion:Ischemic preconditioning before hepatic ischemia/reperfusion could protect the rat liver against ischemia/reperfusion injury after 70%partial hepatectomy. Partâ…¡The Impact of Ischemic Preconditioning on Liver Regeneration in the Ischemia/Reperfusion Injury RatsObjective:Studying the effects of liver regeneration after partial hepatectomy in hepatic ischemia/reperfusion and hepatic ischemic preconditioning settings,in order to explore the promotion of hepatic ischemic preconditioning to liver regeneration after ischemia/reperfusion.Methods:The orthotopic partial hepatic ischemia/reperfusion after partial hepatectomy animal model was used.144 Male Sprague Daweley rats were divided into group IR,group IP and group PH.Liver tissues were harvested at 0,1,3,6,12,24,48 and 72 hour after partial hepatectomy in three groups.PCNA was detected by immunohistochemistry and half-quantitative analysis was made to study its expression changes in three groups settings.Calculate the degree of liver regeneration by wet weight and measure the liver cell nuclear mitosis index(MI)by histopathology.Results:(1)The expression of PCNA increased slightly after partial hepatectomy in PH group,its peak time occurred at 24～48 hours after hepatectomy,then decreased lower and lower.Compared with PH group, the expression of PCNA in IR group was significantly lower at 6～72 hours after reperfusion(P＜0.05).Compared with IR group,the expression of PCNA in IP group was significantly higher at 6～72 hours after reperfusion(P＜0.05).(2)The degree of liver regeneration in three groups increased gradually after 24 hours of partial hepatectomy. Compared with PH group,the degree of liver regeneration in IR group was significantly lower at 24-,48-and 72 hours after partial hepatectomy (P＜0.05).Compared with IR group,the degree of liver regeneration in IP group was significantly higher at 24-,48-and 72 hours after partial hepatectomy(P＜0.05).(3)MI increased gradually after 24 hours of partial hepatectomy in three groups,its peak time occurred at 48 hours after hepatectomy,then decreased lower and lower.Compared with PH group,MI in IR group was significantly lower at 24-,48-and 72 hours after partial hepatectomy(P＜0.05).Compared with IR group,MI in IP group was significantly higher at 24-,48-and 72 hours after partial hepatectomy(P＜0.05).Conclusion:Ischemia/reperfusion can restrain the rat liver regeneration after 70%partial hepatectomy,but ischemic preconditioning could attenuate Ischemia/reperfusion injury of the rat liver and promote liver regeneration. Partâ…¢The Impact of Ischemic Preconditioning on the Liver Regeneration Pathway of TNF-α/IL-6/STAT3 in RatsObjective:To investigate the effects of ischemia/reperfusion and ischemic preconditioning on the rats liver regeneration pathway of TNF-α/IL-6/STAT3 and liver cell cycle.Methods:144 Male Sprague Daweley rats were divided into group IR,group IP and group PH.The orthotopic partial hepatic ischemia/reperfusion after partial hepatectomy animal model was used. Rats subjected to 30-min partial liver ischemia,preceded by 10-min preconditioning.Liver tissues were harvested at 0,1,3,6,12,24,48 and 72 hour after partial hepatectomy in three groups,detected the expression of tumor necrosis factor-a(TNF-a)and Interlukin-6(IL-6)by ELISA and NF-kB,STAT3,Cyclin D₁ mRNA by RT-PCR.Results:(1)In PH group,the expression of TNF-a increased rapidly after partial hepatectomy,its peak time occurred at 1 hours after hepatectomy,then decreased lower and lower.Compared with PH group, the expression of TNF-a in IR group was significantly higher at 1～6 hours after hepatectomy(P＜0.05),but lower at 24～72 hours after hepatectomy(P＜0.05).Compared with IR group,the expression of TNF-a in IP group was significantly lower only at 1～6 hours after reperfusion(P＜0.05).(2)In PH group,the expression of IL-6 increased gradually after partial hepatectomy.The peak was at 6 hours after hepatectomy,then the level decreased lower and lower.Compared with PH group,the expression of IL-6 in IR group was significantly lower after hepatectomy(P＜0.05).Compared with IR group,the expression of TNF-a in IP group was significantly higher after reperfusion(P＜0.05).(3) In PH group,the expression of NF-kB and STAT3 mRNA increased after partial hepatectomy and the peak was about 1～3 hours after hepatectomy. But the expression of Cyclin D₁ mRNA increased at 12～72 hours after partial hepatectomy and the peak was at 24 hours after hepatectomy. Compared with PH group,the expression of NF-kB,STAT3 and Cyclin D₁ mRNA in IR group was significantly lower after hepatectomy (P＜0.05).Compared with IR group,the expression of NF-kB,STAT3 and Cyclin D₁ mRNA in IP group was significantly higher after reperfusion(P＜0.05)and make the expression of STAT3 and Cyclin D₁ mRNA forward.Conclusion:(1)Ischemic preconditioning can decrease the expression of TNF-a in the early reperfusion after ischemia/reperfusion, and lessen liver ischemia/reperfusion injury.(2)Ischemic preconditioning can promote liver regeneration after ischemia/reperfusion,this effect may be related to increase expression of IL-6 which was the promoter of liver regeneration.(3)The mechanism of ischemic preconditioning promoting liver regeneration from ischemia/reperfusion injury after partial hepatectomy may be associated with the activation of liver regeneration pathway of TNF-α/IL-6/STAT3.(4)The mechanism of ischemic preconditioning promoting liver regeneration may be complicated and be associated with several signal pathway,and it need to be investigated further more.Partâ…£The Effects of Ischemia/reperfusion and Ischemic Preconditioning on Cell Apoptosis and Proliferation of Liver after partial Hepatectomy in RatsObjective:To study the effects of ischemia/reperfusion and ischemic preconditioning on the rats liver cell apoptosis and proliferation after partial hepatectomy.Methods:The orthotopic partial hepatic ischemia/reperfusion after partial hepatectomy animal model was used.144 Male Sprague Daweley rats were divided into group IR,group IP and group PH.Liver tissues were harvested at 0,1,3,6,12,24,48 and 72 hour after partial hepatectomy in three groups.Flow cytometry was used to detect Ki-67 antigen and cell apoptotic index,which were acted as the quantify of apoptosis and proliferation.Results:(1)The index of cell apoptosis increased slightly after reperfusion in IR group,its peak time occurred at 12 hour after reperfusion,then decreased lower and lower.Compared with IR group,the index of cell apoptosis in IP group was significantly lower(P＜0.05).(2) The expression of Ki-67 in three groups increased after partial hepatectomy,the peak time occurred at 24 hour after partial hepatectomy,then decreased lower and lower..Compared with PH group, the expression of Ki-67 in IR group was significantly lower after partial hepatectomy(P＜0.05).Compared with IR group,the expression of Ki-67 in IP group was significantly higher after partial hepatectomy(P＜0.05).Conclusion:Ischemic preconditioning before hepatic ischemia/ reperfusion could decrease cell apoptosis and promote cell proliferation after 70%partial hepatectomy,it may be the effect of ischemic preconditioning promote liver regeneration.