Effect of L-arginine on myoglobin-induced acute renal failure in the rabbit

Because myoglobin is a potent inhibitor of nitric oxide (NO), we tested whether myoglobin infusion results in renal vasoconstriction and dysfunction, on which L-arginine, a source of NO, has a protective effect in sedated, nondehydrated, and nonacidotic rabbits. The infusion of myoglobin (375 mg/kg) resulted in a decrease in renal blood flow, an increase in renal vascular resistance, and a decrease in creatine clearance associated with a decrease in urinary excretory rate of nitrite/nitrate and guanosine 3',5'-cyclic monophosphate (cGMP). These values 1-2 h after the infusion were significantly different from baseline levels. Co-administration of L-arginine (150 mg/kg bolus followed by 150 mg.kg(-1).min(-1) reversed these changes significantly with attenuation of urinary excretory rate of nitrite/nitrate and cGMP. This study suggests that the myoglobin-induced renal vasoconstriction and dysfunction and protective effect of L-arginine on these outcomes could be mediated through the NO system.