Renal cortical blood flow distribution in obstructive nephropathy in rats

Abstract

To examine the role of intrarenal hemodynamics in obstructive nephropathy, the cortical blood flow distribution (CBFD) was determined in rats with bilateral ureter occlusion (BUO) and unilateral ureter occlusion (UUO) during and after release of obstruction. Prior to release of obstruction of 24 hr duration, it was found that outer cortical perfusion decreased by 20 ± 5% in both BUO and UUO rats. Furthermore, 1 hr after release of BUO, there was rapid normalization of CBFD associated with a modest return of the glomerular filtration rate (GFR), an almost complete return of renal blood flow (RBF), and a marked postobstructive diuresis. In contrast, after release of UUO, the outer cortical perfusion remained decreased by 21 ± 3%, both GFR and RBF remained markedly depressed, and no diuresis occurred. These data demonstrate a marked ischemia of the outer cortex in both BUO and UUO during obstruction; a rapid return of CBFD to a normal pattern after release of BUO; but a persistent outer cortical ischemia following release of UUO.