AJP - Regulatory, Integrative and Comparative Physiology, Vol 270, Issue 5 1092-R1098, Copyright © 1996 by American Physiological Society

ARTICLES

Rapid elicitation of salt appetite by an intravenous infusion of angiotensin II in rats

D. A. Fitts and R. L. Thunhorst
Department of Psychology, University of Washington, Seattle 98195-1525, USA.

A role for the renal renin-angiotensin system in the direct stimulation of salt appetite in the rat remains controversial because attempts to elicit the behavior by intravenous administration of angiotensin II (ANG II) have been unconvincing. We recently demonstrated that depletion-induced salt appetite was attenuated by selective blockade of peripheral ANG II synthesis with an intravenous dose of converting enzyme inhibitor [captopril (Cap)] that does not block the synthesis of ANG II inside the blood brain barrier. We now show that intravenous ANG II at 30 ng/min rapidly reestablishes salt appetite in Cap-blocked rats. The mean arterial blood pressure (MAP) of unblocked, sodium-depleted rats was normal, but Cap-blocked, depleted rats had low MAP. An intravenous infusion of ANG II in Cap-blocked rats brought MAP into the normal range and elicited water and salt drinking within 90 min. Phenylephrine also normalized MAP but failed to elicit fluid intake in Cap-blocked, sodium-deficient rats. Sodium and water balances tended to be more positive during ANG II than during phenylephrine infusions. Thus circulating ANG II may stimulate both thirst and salt appetite by a direct action on the brain and not by causing natriuresis or by raising the blood pressure.

This article has been cited by other articles:

				J. C. Geerling and A. D. Loewy Central regulation of sodium appetite Exp Physiol, February 1, 2008; 93(2): 177 - 209. [Abstract] [Full Text] [PDF]

				D. A. Fitts, J. A. Freece, J. E. Van Bebber, D. K. Zierath, and J. E. Bassett Effects of forebrain circumventricular organ ablation on drinking or salt appetite after sodium depletion or hypernatremia Am J Physiol Regulatory Integrative Comp Physiol, December 1, 2004; 287(6): R1325 - R1334. [Abstract] [Full Text] [PDF]

				Y. K. Cho, M. E. Smith, and R. Norgren Low-dose furosemide modulates taste responses in the nucleus of the solitary tract of the rat Am J Physiol Regulatory Integrative Comp Physiol, October 1, 2004; 287(4): R706 - R714. [Abstract] [Full Text] [PDF]

				D. A. Fitts, S. N. Thornton, A. A. Ruhf, D. K. Zierath, A. K. Johnson, and R. L. Thunhorst Effects of central oxytocin receptor blockade on water and saline intake, mean arterial pressure, and c-Fos expression in rats Am J Physiol Regulatory Integrative Comp Physiol, December 1, 2003; 285(6): R1331 - R1339. [Abstract] [Full Text] [PDF]

				R. L. Thunhorst and A. K. Johnson Thirst and salt appetite responses in young and old Brown Norway rats Am J Physiol Regulatory Integrative Comp Physiol, February 1, 2003; 284(2): R317 - R327. [Abstract] [Full Text] [PDF]

				R. L. Thunhorst and A. K. Johnson Effects of hypotension and fluid depletion on central angiotensin-induced thirst and salt appetite Am J Physiol Regulatory Integrative Comp Physiol, November 1, 2001; 281(5): R1726 - R1733. [Abstract] [Full Text] [PDF]

				G. H. M. Schoorlemmer, A. K. Johnson, and R. L. Thunhorst Circulating angiotensin II mediates sodium appetite in adrenalectomized rats Am J Physiol Regulatory Integrative Comp Physiol, September 1, 2001; 281(3): R723 - R729. [Abstract] [Full Text] [PDF]

				D. A. Fitts, E. M. Starbuck, and A. Ruhf Circumventricular organs and ANG II-induced salt appetite: blood pressure and connectivity Am J Physiol Regulatory Integrative Comp Physiol, December 1, 2000; 279(6): R2277 - R2286. [Abstract] [Full Text] [PDF]

				R. L. Thunhorst, T. G. Beltz, and A. K. Johnson Effects of subfornical organ lesions on acutely induced thirst and salt appetite Am J Physiol Regulatory Integrative Comp Physiol, July 1, 1999; 277(1): R56 - R65. [Abstract] [Full Text] [PDF]

				N. E. Rowland and K. R. Morian Roles of aldosterone and angiotensin in maturation of sodium appetite in furosemide-treated rats Am J Physiol Regulatory Integrative Comp Physiol, May 1, 1999; 276(5): R1453 - R1460. [Abstract] [Full Text] [PDF]

				D. A. Fitts, J. R. Lane, E. M. Starbuck, and C.-P. Li Drinking and blood pressure during sodium depletion or ANG II infusion in chronic cholestatic rats Am J Physiol Regulatory Integrative Comp Physiol, January 1, 1999; 276(1): R23 - R31. [Abstract] [Full Text] [PDF]

				J. T. FITZSIMONS Angiotensin, Thirst, and Sodium Appetite Physiol Rev, July 1, 1998; 78(3): 583 - 686. [Abstract] [Full Text] [PDF]