Elevated dietary salt suppresses renin secretion but not thirst evoked by arterial hypotension in rats

Sean D. Stocker, Carrie A. Smith, Celeste M. Kimbrough, Edward M. Stricker, Alan F. Sved

Research output: Contribution to journalArticlepeer-review

17 Scopus citations

Abstract

Increased dietary salt intake was used as a nonpharmacological tool to blunt hypotension-induced increases in plasma renin activity (PRA) in order to evaluate the contribution of the reninangiotensin system (RAS) to hypotension-induced thirst. Rats were maintained on 8% NaCl (high) or 1% NaCl (standard) diet for at least 2 wk, and then arterial hypotension was produced by administration of the arteriolar vasodilator diazoxide. Despite marked reductions in PRA, rats maintained on the high-salt diet drank similar amounts of water, displayed similar latencies to drink, and had similar degrees of hypotension compared with rats maintained on the standard diet. Furthermore, blockade of ANG II production by an intravenous infusion of the angiotensin-converting enzyme inhibitor captopril attenuated the hypotension-induced water intake similarly in rats fed standard and high-salt diet. Additional experiments showed that increases in dietary salt did not alter thirst stimulated by the acetylcholine agonist carbachol administered into the lateral ventricle; however, increases in dietary salt did enhance thirst evoked by central ANG II. Collectively, the present findings suggest that hypotension-evoked thirst in rats fed a high-salt diet is dependent on the peripheral RAS despite marked reductions in PRA.

Original languageEnglish (US)
Pages (from-to)R1521-R1528
JournalAmerican Journal of Physiology - Regulatory Integrative and Comparative Physiology
Volume284
Issue number6 53-6
DOIs
StatePublished - Jun 1 2003

All Science Journal Classification (ASJC) codes

  • Physiology
  • Physiology (medical)

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