Role of the pituitary in controlling aldosterone production in sodium-depleted rats.

Abstract

In sodium-depleted rats an intact pituitary was found to be essential for normal stimulation and maintenance of aldosterone production. To define better this pituitary involvement the effects on aldosterone production of whole and posterior pituitary extracts, ACTH, GH, FSH, LH and l-thyroxin injections were studied in hypophysectomized rats fed a diet low in sodium. None of the injections resulted in aldosterone secretion rates which approached those measured in intact, sodium-depleted rats. Whole pituitary extracts, ACTH and GH had some aldosterone stimulatory effect. In order to avoid the effects of prolonged hypophysectomy, rats were first sodium depleted and then hypophysectomized. The ability of pituitary hormones to maintain the elevated aldosterone secretion and in vitro production rate was studied. ACTH only partially maintained aldosterone secretion and in vitro production while maintaining corticosterone production in vitro. GH also partially maintained aldosterone secretion and production but ...