Split intrarenal hemodynamics in renovascular hypertension

Abstract

Split intrarenal hemodynamics in stenotic and contralateral kidneys of unilateral renovascular hypertension (RVH) were estimated by Gomez's formulae. Ten patients with RVH were studied. Split para-amino hippurate and inulin clearances were measured by ureteral catheterization as indexes for renal plasma flow and glomerular filtration rates, allowing the estimation of intrarenal hemodynamics such as preglomerular arteriolar resistance, postglomerular arteriolar resistance and glomerular hydrostatic pressure in each kidney. Renal plasma flow and glomerular filtration rates were lower in the stenotic kidney (83 +/- 12, 19 +/- 2 ml/min/m2) than in the contralateral kidney (170 +/- 19, 43 +/- 4). Preglomerular arteriolar resistance was elevated due to the stenotic lesion in the stenotic kidney (30,900 +/- 4,500 dyns.sec.cm-5) while the elevation in the contralateral kidney (11,300 +/- 1,000) was less. Postglomerular arteriolar resistance was high in both kidneys. Glomerular pressure was lowered in the stenotic kidney (54 +/- 1 mmHg), while elevated in the contralateral kidney (71 +/- 3). Although the stenotic kidney of RVH was protected from systemic hypertension (138 +/- 6 mmHg) by stenosis of the renal artery, the increase in preglomerular arteriolar resistance in the contralateral kidney was not sufficient, making glomerular pressure elevated. Thus, glomerular hypertension and hyperfiltration were demonstrated in the contralateral kidney of RVH.