INTRA-RENAL HEMODYNAMICS AND RENAL-FUNCTION IN POST-OBSTRUCTIVE UROPATHY

Abstract

Impairment of renal function was noted after release of 24 h of unilateral (UUO) and bilateral (BUO) ureteral obstruction. After release of obstruction fractional Na excretion was identical in obstructed and intact kidneys of UUO rats; massive natriuresis occurred in BUO rats. Renal blood flow in BUO rats, determined by the microsphere method after release of 24 h of obstruction, was approximately 60% of control values. Mean renal blood flow of the obstructed kidney of UUO rats after release of obstruction was 78% of the mean renal blood flow of the contralateral unobstructed kidney. No redistribution of intrarenal blood flow was noted in UUO and BUO rats. Filtration fractions of obstructed kidneys from BUO and UUO rats after release of obstruction were lower than those of controls, suggesting that preglomerular vasoconstriction is primarily involved in the reduction of glomerular filtration rate.