Aldosterone in vitro restores nephron Na-K-ATPase of distal segments from adrenalectomized rabbits.

Aldosterone, when added in vitro to defined nephron segments, dissected from adrenalectomized rabbits, restores the depressed Na+-K+-ATPase activity in the thick ascending limb of the loop of Henle and in the cortical collecting tubule within 1 h of incubation. The direct effect is specific and, as demonstrated for the cortical collecting tubule, dose-dependent. The time course of aldosterone-mediated Na+-K+-ATPase activation is compatible with the conjecture of changes in the enzyme lipid environment.