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

DAMAGE of the supraoptic nuclei, the paraventricular nuclei, the supraoptico-hypophyseal tract or the neurohypophysis results in the development of diabetes insipidus (Fisher, Ingram and Ranson, 1938; Smith, 1951). Accordingly, the secretion of the antidiuretic hormone (ADH) appears to be dependent upon the integrity of the supraoptico-hypophyseal system. Since adrenalectomy results in an increased reabsorption of water by the renal tubules and a diminished diuretic response to a water load, it has been postulated that the secretion of the antidiuretic hormone is dependent also upon the integrity of the adrenal cortex (Gaunt, Birnie and Eversole, 1949). Direct evidence in support of the aforementioned was not available until Birnie, Jenkins, Eversole and Gaunt (1949) demonstrated that the antidiuretic activity of the serum of rats is elevated after adrenalectomy. Although the procedure employed by Birnie et at. (1949, 1950) undoubtedly permits the detection of antidiuretic substances, the significance of their findings was questioned by studies which suggested that the antidiuretic activity of serum