Angiotensin II infusion increases vasopressin, ACTH, and 11-hydroxycorticosteroid secretion

The effects of intravenous infusion of Asp1, Ile5-angiotensin II on blood pressure, plasma vasopressin, ACTH and 11-hydroxycorticosteroid levels and on plasma renin activity were studied in five trained, conscious dogs. The dogs were prepared with bilateral carotid loops. Infusion of angiotensin II at rates of 5, 10, and 20 ng/kg.min raised its plasma concentration from 23 ± 7 to 48 ± 8, 125 ± 8, and 187 ± 21 pg/ml, respectively. The lowest rate of infusion was mildly pressor, the two higher rates more so. All rates of infusion promptly increased vasopressin levels and depressed renin levels. The two higher rates also stimulated ACTH, although with a latency of 30-45 min. Since the rates of infusion of angiotensin II employed produced plasma levels within the physiological range, it is suggested that peripherally generated angiotensin II may play an important role in the regulation of vasopressin, and ACTH secretion.