Role of Potassium in the Control of Aldosterone Secretion in the Rat

In the rat, dietary sodium depletion results in an increased conversion of corticosterone to aldosterone, an increase in zona glomerulosa width, and a sustained increase in aldosterone production with no increase in corticosterone secretion. In the present studies, oral potassium loading has been shown to lead to similar changes in adrenal steroidogenesis: an increased conversion of corticosterone to aldosterone and a sustained increase in aldosterone production without increased corticosterone secretion. It was also found that potassium-deficient rats do not respond normally to sodium depletion. Further, it was noted that arterial plasma potassium concentration increased significantly during sodium depletion. It is concluded that the potassium ion is an important regulator of adrenal function in the rat, playing a significant role in the mediation of the zona glomerulosa response to sodium depletion. (Endocrinology88: 556, 1971)