Renal Baroreceptor Control of Acute Renin Release in Normotensive, Nephrogenic and Neurogenic Hypertensive Dogs

Abstract

Graded reductions in mean renal perfusion pressure cause kidneys of normotensive, renal, and neurogenic hypertensive dogs to release renin. In anesthetized normal dogs with mean resting pressures of 110 to 150 mm Hg, increased renin secretion occurred at renal perfusion pressures of 90 to 120 mm Hg. In dogs hypertensive from constriction of a renal artery, pressure beyond the constriction was within the normal range, and lowering of renal perfusion pressure caused release in the same range as in normal dogs. In dogs with neurogenic hypertension due to section of the carotid sinus and aortic depressor nerves, return was released at perfusion pressures within, or only slightly above, the normal range. In sharp contrast with these three groups, renin was released in dogs with hypertension due to perinephritis at mean pressures of 140 to 165 mm Hg when lowered from resting levels of 180 to 220 mm Hg. This different range could depend either upon reduced intrarenal pressure which mimicks the effects of a renal artery clamp or upon a change in range of response of the renal baroreceptor due to some more direct effect of the perinephritic hull. No evidence was found that the renal baroreceptor control of renin secretion is nonfunctional in dogs with renal hypertension.