Sympathetic system in potassium homeostasis

Abstract

The extrarenal disposal of K was studied in nephrectomized and adrenalectomized rats by measuring the rise in serum K produced during an infusion of 3 meq KCl/kg over 90 min. Adrenalectomy alone did not alter the volume of distribution of infused K in nephrectomized animals. When nephrectomy and adrenalectomy were combined with either insulin deficiency produced by streptozotocin or chemical sympathectomy induced by injection of 6-hydroxydopamine, K tolerance was significantly impaired. Hyperkalemia produced in chemically sympathectomized animals by K infusion was minimized by simultaneous infusion of epinephrine, an effect blocked by the .beta.-antagonist propranolol but not by the .alpha.-blocker phenoxybenzamine. Apparently, extrarenal uptake of K, in addition to being influenced by insulin and circulating catecholamines, is modulated by peripheral sympathetic activity.