Ischemic and reperfusion syndrome of hind limbs: functional and histological renal changes in rats

RESUMO

Ischemic and reperfusion injury of the extremities may result in a systemic, severe and complex metabolic syndrome, manifested by acute renal failure, myoglobinuria, metabolic acidosis, hipercalemia and free radicals releasing. We investigated the functional and histologic renal changes after ischemia and reperfusion of the hind limb skeletal muscles. Rats were submitted to the ligature of the infrarenal aorta for 6 and 12 h. The animals were then randomized into four groups of 10 rats Group I, 6 h of ischemia and 24 h of reperfusion; Group II, 12 h of ischemia and 24 h of reperfusion; Group III, 6 h of ischemia and 10 days of reperfusion; and Group IV, Group sham with no ischemia or reperfusion. Blood samples at the end of the experiment and urine volume in the first 24 h of reperfusion in group I and II and in the last day in group III for functional analysis were collected. The following renal functional parameters were studied creatinine plasmatic level, creatinine depuration and sodium urinary/creatinine urinary ratio. The kidneys were removed and a histological tubulo-interstitial lesional index was evaluated for each animal. We found higher plasma creatinine levels and morphologic changes in groups submitted to ischemia and reperfusion. Ten days after reperfusion, the histologic changes persisted despite the recovery of renal function.