Central administration of atrial natriuretic peptide suppresses sodium and water intake of sheep

The effect of intracerebroventricular (i.c.v.) infusion (20 μg/h over 3 h) of human α-atrial natriuretic peptide (ANP) on Na and water intake of sheep was studied. I.c.v. infusion of ANP decreased ( P < 0.01) Na and water intakes of water-deprived sheep but did not affect significantly Na or water intakes of Na and water-replete sheep. In addition, i.c.v. infusion of ANP decreased ( P < 0.05) Na and water intakes of sheep infused i.c.v. with angiotensin II. The results suggest that ANP may act on brain mechanisms concerned with both Na appetite and thirst. These mechanisms may involve action on the angiotensin II component of sodium appetite but effects on other factors determinant of appetite cannot be excluded at present.