Protective effects of carnosine and melatonin on hepatic ischemia reperfusion injury

ABSTRACTProtective Effects of Carnosine and Melatonin on Hepatic Ischemia-Reperfusion InjuryDr. Başak BaykaraHistology and Embryology Department, Faculty of Medicine, Dokuz Eylül University,İnciraltı, İzmir, TurkeyAİMHepatic ischemia and subsequent reperfusion cause hepatic injury and apoptosis.The aim of this study is to investigate the light microscopic, biochemical andimmunohistochemical effects of antioxidant agents, carnosine (CAR) and melatonin(MEL), in hepatic ischemia reperfusion injury.MATERIAL AND METHODFive study groups were formed. The groups are; I. Sham-operated, II. Ischemia/reperfusion (IR), III. IR+MEL, IV. IR+CAR, V. IR+CAR+MEL Total hepatic ischemia isapplied for 1 hour and reperfusion period is applied for 4 hours. CAR (250/mg/kg)and MEL (10/mg/kg) were administered 30 minutes prior to the ischemia period andimmediately before the reperfusion period, intraperitoneally. Tissue samples wereprepared for light microscopy. Light microscopic preparations were stained withhematoxylin-eosine. Electron microscopic semithin preparations were stained withtoluidin blue. Apoptotic cells were demonstrated by apostain ALT, AST levels weremeasured in serum. TBARS, MPO and GR were measured in hepatic tissuehomogenate.RESULTSIn ischemia reperfusion group, diffuse hepatocyte injury, dilated sinusoids, congetionand neutrophil infiltration was observed however in treatment groups these changeswere seen much less than ischemia reperfusion group. ALT, AST and MPO levelswere increased in IR group, also those levels were decreased in treatment groups.GR level was decreased in IR group, on the contrary, increased in KAR andKAR+MEL groups. There was no difference in TBARS levels between groups.Number of apoptotic cells were increased in IR group and decreased in treatmentgroups, in apostain stained sections.CONCLUSIONTreatment of carnosine is much more effective than melatonin for recovering ofstructural and biochemical changes in ischemia reperfusion injury, neverthelesstreatment of melatonin and carnosine together is much more effective for recoveringfrom ischemia reperfusion injury.Key Words: Liver, ischemia, reperfusion injury, carnosine, melatonin