Renal responses of the cardiac-denervated nonhuman primate to blood volume expansion

Abstract

Experiments were performed to determine whether total, specific cardiac denervation affects the renal responses of the nonhuman primate to acute intravascular volume expansion. Adult male Macaca fascicularis monkeys underwent chronic intrapericardial cardiac denervation or sham surgery. After a 14- to 30-day recovery period, each animal was anesthetized with sodium pentobarbital and estimated blood volume was volume-expanded 20% with 6% dextran in isotonic saline. Control renal excretory function did not differ between the two groups, and both groups had similar increases in urine flow, sodium and potassium excretion, osmolar clearance, free water clearance, and renal plasma flow after volume expansion. The times to peak diuresis and natriuresis also were similar in both groups. These results demonstrate that the cardiac-denervated monkey shows unattenuated renal excretory responses to volume expansion. This could indicate that either cardiac receptors do not play a major role in eliciting these responses in the primate or that eliminating a role of cardiac afferents is compensated for by redundant afferents from arterial baroreceptors.