The role of L-arginine and aerobic exercise in experimental renal ischemia reperfusion injury in male and female rats

Introduction: Renal ischemia/reperfusion (I/R) injury due to reactive oxygen species (ROS) formation is the main cause of acute kidney damage. Nitric oxide (NO) biosynthesis and oxidative stress are closely related to the pathogenesis of renal I/R injury. This study was undertaken to determine the effects of L-arginine (L-arg) as NO donor and aerobic exercise (EX) and also the combination of L-arg with EX on renal I/R injury in male and female rats. Methods: 54 male and female Wistar rats were divided into four groups in each gender as control, L-arginine (L-arg), treadmill exercise (EX), and L-arginine plus exercise (L-arg & EX). After 8 weeks of EX, animals were exposed to 45 min of bilateral kidney ischemia followed by 24 hours of reperfusion. We assessed serum creatinine (Cr), Kidney tissue damage score (KTDS), kidney weight (KW), serum nitrite and malondialdehyde (MDA) levels. Results: L-arg, EX or combination of L-arg &EX caused a significant decrease in serum level of creatinine (Cr) (P<0.05). KTDS decreased significantly in all female treated groups and male L-arg treated group (P<0.05) when compared with the control group. However, the kidney weight was decreased significantly in male rats (P<0.05) at 24 hr post reperfusion, and such observation was not seen in female. No significant differences were detected in serum nitrite levels between the groups, but combination of L-arg &EX decreased the serum level of malondialdehyde (MDA) in female significantly (P<0.05). Conclusion: Pretreatment with L-arg seems to have protective effects against renal I/R injury. The protective effect of exercise against renal I/R injury seems to be less than L-arg but the reno-protective effect of EX increases when combined with L-arg.