Angiotensin II-Induced Vasopressin Release is Attenuated by Central Atrial Natriuretic Factor

Abstract

Administration of angiotensin II (Ang II) into the cerebral ventricles (icv) of rats elicits vasopressin release and an increase in blood pressure. The effect of atrial natriuretic factor (ANF) on these actions of ANG II was studied in conscious spontaneously hypertensive rats. The magnitude and time course of the blood pressure increase following ANG II (50 and 100 ng) were not altered by ANF, icv. However, vasopressin levels which were stimulated from 10.8 +/- 1.5 to 62.1 +/- 6.4 pq/ml by ANG II (100 ng) were significantly suppressed by combined administration of ANG II (100 ng) and ANF (3 ug/kg) (33.0 +/- 4.3 pg/ml). The injection of ANF alone into the cerebral ventricles had no effect on resting blood pressure or vasopressin levels. Peripheral administration of ANF was unable to attenuate the ANG II-induced vasopressin release. These data suggest that there exists a central interaction of ANF and ANG II within the brain which cannot be mimicked by peripheral administration of ANF.