THE ANTIDIURETIC ACTIVITY OF THE PLASMA OF ADRENALECTOMIZED, HYPOPHYSECTOMIZED AND ADRENALECTOMIZED-HYPOPHYSECTOMIZED RATS12

Abstract

The antidiuretic activity of the plasma of rats is increased markedly in 18 hours after adrenalectomy. Plasma of animals adrenalectomized 7 days previously and maintained with 1% NaCl for 5 days has a still greater antidiuretic activity. The activity of the plasma from animals adrenalectomized 30 days previously and maintained with NaCl for 28 days approaches that of unoperated rats. Administration of cortisone prevents the increased activity noted in 18 hours and 7 days after adrenalectomy. Complete hypophysectomy results in a significant diminution in the antidiuretic activity of the plasma. Subsequent adrenalectomy, however, produces a relatively rapid and marked augmentation in the activity of the plasma. Consequently, the major source of the antidiuretic activity must be some site other than the neurohypophysis The effect of adrenalectomy is attributed to a non-specific activation of the hypothalamic-hypophyseal system by the noxious changes associated with the insufficiency of the corticosteroids produced by the zona glomerulosa.