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(Reference retrieved automatically from Web of Science through information on FAPESP grant and its corresponding number as mentioned in the publication by the authors.)

Non-NMDA receptors in the lateral parabrachial nucleus modulate sodium appetite

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Author(s):
De Gobbi, Juliana I. F. [1] ; Beltz, Terry G. [1] ; Johnson, Ralph F. [1] ; Menani, Jose Vanderlei [1] ; Thunhorst, Robert L. [1] ; Johnson, Alan Kim [2]
Total Authors: 6
Affiliation:
[1] Univ Iowa, Ctr Cardiovasc, Iowa City, IA 52242 - USA
[2] Univ Iowa, Dept Psychol, Iowa City, IA 52242 - USA
Total Affiliations: 2
Document type: Journal article
Source: Brain Research; v. 1301, p. 44-51, NOV 16 2009.
Web of Science Citations: 23
Abstract

Glutamatergic mechanisms have been implicated in the control of fluid ingestion. In the present study, we investigated whether non-N-methyl-D-aspartate (NMDA) glutamatergic receptors in the lateral parabrachial nucleus (LPBN) are involved in the control of water and sodium intake. Male Sprague-Dawley rats had cannulas implanted bilaterally into the LPBN. They were acutely depleted of water and sodium by injections of the diuretic furosemide (Furo; 10 mg/kg, bw) and given a low dose of the angiotensin-converting enzyme inhibitor, captopril (Cap; 5 mgfkg, bw). Bilateral LPBN injections of the non-NMDA receptor antagonist DNQX (2 and 5 nmol/0.2 mu l) increased the ingestion of 0.3 M NaCl and water of Furo/Cap treated rats. The increased ingestion produced by DNQX was abolished by pretreating the LPBN with alpha-amino-3-hydroxy-5-methylisoxazole-4-propionic acid (AMPA), a non-NMDA receptor agonist. AMPA injected alone into the LPBN reduced water and 0.3 M NaCl intake. Injections of DNQX (5 nmol/0.2 mu l) into the LPBN also produced ingestion of 0.3 M NaCl after sc injections of the beta-adrenoceptor agonist, isoproterenol, a hypotensive drug that typically produces only water intake. Food intake, arterial blood pressure and heart rate were not altered by DNQX LPBN injections. We conclude that agonists acting on non-NMDA receptors in the LPBN exert an inhibitory influence on sodium intake during acute fluid depletion with hypotension and after isoproterenol. treatment. A possible interaction of serotonin with glutamate within the LPBN is discussed. (C) 2009 Elsevier B.V. All rights reserved. (AU)