[Site and mechanism of tubular Na-K-ATPase regulation by aldosterone].
Effects of adrenalectomy and acute administration of physiologic doses of aldosterone on the activity and the number of catalytic units of Na-K-ATPase, the biochemical equivalent of the sodium pump, were evaluated on single microdissected nephron segments. After adrenalectomy, Na-K-ATPase is markedly decreased in all rabbit nephron segments, except the proximal tubule. However, aldosterone administration restores Na-K-ATPase exclusively in the collecting tubule, where mineralocorticoid receptors have been localized. Aldosterone induces both the activity and the appearance of new catalytic units with a kinetics similar to that of the antinatriuretic action of the hormone. These results suggest that Na-K-ATPase might be a primary target for aldosterone action.
D000450:Aldosterone / Q000494:pharmacology*; D000818:Animals; D007684:Kidney Tubules / Q000201:enzymology*; D007685:Kidney Tubules, Collecting / Q000201:enzymology; D011817:Rabbits; D051381:Rats; D012964:Sodium / Q000652:urine; D000254:Sodium-Potassium-Exchanging ATPase / Q000378:metabolism*
D000450:Aldosterone; D012964:Sodium; D000254:Sodium-Potassium-Exchanging ATPase
Site et mécanisme de régulation de la Na-K-ATPase tubulaire par l'aldostérone.