Abstract
The effects of 2hours of renal artery occlusion were studied in pre-viously uninephrectomized rabbits. Oliguric renal failure by arterial clamping was produced. Renal blood flow was maintained during ob-servation periods, except for an early decrease in outer cortical blood flow without change elsewhere. During the oliguric stage medullary osmolality was markedly diminished, concomitantly with reduced (U/P)osm. Cin, EPAH and sodium reabsorption were decreased, accompanied by tubular necrosis and intratubular casts. During the early diuretic stage Cin, medullary osmolality and (U/P)osm were still reduced. Intratubular casts disappeared while regenerated tubular cells were focally observed. Two weeks after the occlusion, improved Cin, EPAH, sodium reabsorption, medullary osmolality and (U/P)osm, and regenerated tubular epithelium were found. In 7 weeks Cin and EPAH had returned to the preclamping values whereas medullary osmolality remained decreased with the ap-pearance of medullary fibrosis. (U/P)osm was not completely restored. The findings indicate that during the oliguric stage of acute renal failure of rabbits renal blood flow is maintained, except for a decrease in outer cortical flow, and urine concentrating ability is restored more slowly than other measured functions.
