[Effect of pretreatment with melatonin on the oxidative and inflammatory damage induced by hepatic ischemia/reperfusion in Zucker rats].

The limiting factor of the viability of hepatic transplants has been the ischemia reperfusion damage where oxidative stress induced lesion after reperfusion plays a fundamental role. Melatonin is a substance that has demonstrated protective effects against oxidative stress. The aim of the present study is to demonstrate that the intraperitoneal or oral administration of melatonin before and during experimental hepatic ischemia reperfusion in young and old Wistar and Zucker rats could reduce the oxidative stress and inflammation induced lesion, responsible of the poor initial function after ischemia in the old or steatosic livers. The mRNA expression in hepatic tissue of cytokines, markers of oxidative stress and apoptosis as well as plasma transaminase levels were analyzed. Results showed an increase in both plasma transaminase as well as cytokines or oxidative stress and proapoptotic parameters. The elevation was higher in old and Zucker rats. Treatment with melatonin significantly reduced hepatic damage, being oral administration more effective. In conclusion melatonin was able to reduce liver damage after ischemia reperfusion being the effect more important in old and Zucker animals.