Role of glucoregulatory hormones in potassium homeostasis

Abstract

An incompletely defined interregulatory balance exists between potassium, insulin, and aldosterone. That potassium administration enhances and hypokalemia depresses aldosterone production is well known. It is not as well known that the same relationship exists between potassium and insulin. In a normal subject, acute hyperkalemia stimulates release of insulin from the pancreas. Potassium deficiency, on the other hand, may depress production of insulin. Both insulin and aldosterone, under appropriate conditions, may indirectly promote transfer of potassium ions from extracellular to intracellular fluid. In contrast, deficiency of either insulin or aldosterone, and especially both, may favor development of hyperkalemia. Pharmacologically, glucagon, epinephrine, norepinephrine, and somatotropin may also influence transfer of potassium between extracellular and intracellular fluid. Their precise physiological roles in potassium homeostasis, however, are much less evident than that for insulin and aldosterone. It is the intention of this brief review to point out the salient effects and mechanisms whereby the foregoing substances affect potassium homeostasis and to point out physiologically important interrelationships wherever possible.