Sodium- and potassium-activated ATPase. A possible target of aldosterone.

Regulation by adrenal corticosteroids of sodium and potassium transport in loop of Henle and distal tubule of rat kidney.

“…Adrenalectomy reduces the activity of Na,K-ATPase in both the cortical and medullary segments of the thick ascending limb (34)(35)(36)(37)(38)(39)(40)(41). Although early studies indicated that aldosterone was capable of increasing the activity of Na,K-ATPase after adrenalectomy (36,39,40), more recent studies have shown that dexamethasone but not aldosterone increases enzyme activity (34,35,38 (6) did not observe an effect of an aute infusion of aldosterone on potassium reabsorption in the loop of Henle. This latter observation contrasts with the results in the present study, in which chronic aldosterone treatment stimulated potassium reabsorption.…”

Regulation of renal Na-K-ATPase in the rat. Role of the natural mineralo- and glucocorticoid hormones.

“…Both mineralo-and glucocorticoids influence important transport and metabolic functions of the kidney, and among their proposed mechanisms of action is a direct or indirect stimulatory effect on renal sodium-and potassium-activated adenosine triphosphatase (Na-K-ATPase)' (1)(2)(3)(4). The role of adrenal steroids in the regulation of renal Na-K-ATPase has been amply documented by ablative studies, which invariably show a substantial decline in the activity ofthe enzyme after adrenalectomy (ADX) (5)(6)(7)(8)(9)(10)(11)(12)(13)(14)(15)(16)(17).…”

Secondary effect of aldosterone on Na-KATPase activity in the rabbit cortical collecting tubule.

“…The second, or energy theory, held that aldosterone enhanced ion transport primarily by inducing the synthesis of key enzymes involved in the production of ATP, a necessary substrate for active Na transport (4)(5)(6). The third theory, known as the pump theory, maintained that aldosterone augmented the cellular capacity to transport Na by increasing the activity of Na-K ATPase (7)(8)(9).…”