Effects of liver ischemia-reperfusion on renal functional and oxidative stress indices

Liver ischemia/reperfusion (IR) is a major clinical problem, which occurs during several conditions such as liver damage, trauma and transplantation. Recent studies indicate that IR-induced acute liver failure causes injuries of distant organs such as heart and lungs by systematic inflammatory responses. Therefore, in the present study, effects of hepatic IR induction were studied on the kidneys. Male rats were subjected to either sham operation or 90 min liver ischemia followed by 4 or 24 hrs of reperfusion. Liver IR injury was assessed by measurement of serum alanine transaminase (ALT), aspartate transaminase (AST), alkaline phosphatase (ALP) and lactate dehydrogenases (LDH) levels. Blood Urea Nitrogen (BUN) and creatinine (Cr) were determined as renal function indices. Renal malondialdehyde (MDA), superoxide dismutase (SOD) and catalase activities were also evaluated for assessment of oxidative stress. Ninety min liver ischemia followed by 4 hours of reperfusion caused a reduction in renal function demonstrated by an increase in BUN level. This was accompanied by an increase in renal MDA levels and a decrease in SOD and catalase activities. Liver reperfusion for 24 hours resulted in smaller damage to renal function and oxidative stress parameters. This study suggests that liver IR causes renal damage reflected in functional abnormalities and oxidative stress. This damage is reduced by increasing the reperfusion time.