Effect of hemoglobin loads on the function and morphology of ischemic kidneys in the rat

Male Wistar rats were used to investigate the effects of stromafree hemoglobin (200 mg Hb/100 g body weights, i.v. as a 16.4% solution) on kidney function and morphology. Ischemia of the kidney was induced by bilateral clamping of the renal pedicle. The most severe disturbances of kidney function occurred in kidneys damaged by ischemia during the peak of Hb excretion; endogenous creatinine clearance decreased to 5% of control values, serum creatinine concentration rose 6 times as high as control values, and Hb excretion in the urine was reduced. Kidney damage after Hb loading and ischemia was more severe than damage caused by ischemia alone. These results demonstrate that the vulnerability of kidneys to damage by ischemia is increased by Hb loading.