Separated Renal Functions

A THEROSCLEROSIS, fibrous proliferation, or primary dissecting aneurysm of main renal arteries or their primary branches may cause hypertension and can alter renal blood flow, filtration rate, sodium excretion, and water reabsorption." 2 Mechanisms of the changes in sodium and water transport are not fully understood; they may include decreases in intrarenal arterial pressure, glomerular filtration rate, distribution of peritubular blood, and, if renal atrophy is present, some change in tubular function. In dogs, partial constriction of one main renal artery provokes the excretion of urine of diminished volume and sodium concentration, and increased osmolality.3 4 However, if the number of functioning nephrons is decreased by complete occlusion of primary branches of the main renal artery or by unilateral parenchymal disease, urine volume, filtration rate, and osmolality are, alike, decreased.5-7 These experiments indicate that differences in renal functional patterns would be found in hypertensive patients with occlusive renal artery disease depending upon whether the lesion involves the main renal artery, some of its primary branches, or is associated with pyelonephritis. This report describes specific functions of individual kidneys of hypertensive patients with renal artery disease and compares them with those found in pyelonephritis and essential hypertension.