Protective effect of donator liver ischemic preconditioning on posttransplant liver graft function in Chinese miniature pigs / 南方医科大学学报

<p><b>OBJECTIVE</b>To investigate the protective effect of the ischemia preconditioning of the donor liver on posttransplant liver graft function in Chinese miniature pigs.</p><p><b>METHODS</b>Twenty-five partially inbred Chinese miniature pigs were randomized into three groups, namely the normal control group, the ischemia-reperfusion group and ischemic preconditioning group. Biopsies of the liver graft were performed to analyze HSP70 expression by means of immunoblotting, and the changes of serum AST/ALT levels were assayed using an automated biochemical analyzer. Histopathological assessment was carried out to identify the hepatocyte injury using optical and transmission electron microscopy.</p><p><b>RESULTS</b>Ischemia preconditioning resulted in a notable increase in HSP70 expression and milder injury of the hepatocyte microstructure, whereas ischemia-reperfusion caused a significant increase of serum transaminases level (P<0.01) with declined HSP70 expression and obvious microstructural changes of the liver tissue.</p><p><b>CONCLUSION</b>Ischemic preconditioning can produce obvious protective effects on the donor liver, and positively regulates the expression of shock protein.</p>

Protective effect of protein kinase C and mitogen-activated protein kinases and its mechanism in liver ischemic preconditioning / 南方医科大学学报

<p><b>OBJECTIVE</b>To investigate the protective effects of protein kinase C (PKC) and mitogen-activated protein kinases (MAPKs) their and mechanisms in liver ischemic preconditioning.</p><p><b>METHODS</b>In rat models of liver ischemia-reperfusion (IR) and ischemic preconditioning (IP), the liver function was evaluated by examining serum alanine aminotransferase and aspartate aminotransferase levels, and the morphological changes of the liver cells were observed under microscope. PKC activator phorbol 12-myristate 13-acetate(PMA) and inhibitor chelerythrine(CHE), as well as MEK inhibitor PD98059, were utilized to analyze the phosphorylation of PKC and P44/42 MAPKs.</p><p><b>RESULTS</b>Compared with the control rats, the liver function was best protected in rats of IP group, but not in those of IP group with PD98059 or CHE treatment. The rats in IR group showed improved liver function after PMA treatment. Similarly, the phosphorylation of PKC and P44/42 MAPKs was correlated with the liver function, and highly enhanced PKC and P44/42 MAPKs activity was observed in IP and IR+PMA groups, but decreased activity in IR and IP+CHE groups.</p><p><b>CONCLUSION</b>Phosphorylation of PKC and MAPKs plays a pivotal role in the preservation of the hepatocytes during IP.</p>