title: Moxonidine into the lateral parabrachial nucleus modifies postingestive signals involved in sodium intake control.
abstract: The activation of α2-adrenoceptors with bilateral injections of moxonidine (α2-adrenoceptor and imidazoline receptor agonist) into the lateral parabrachial nucleus (LPBN) increases 1.8% NaCl intake induced by treatment with furosemide (FURO)+captopril (CAP) subcutaneously. In the present study, we analyzed licking microstructure during water and 1.8% NaCl intake to investigate the changes in orosensory and postingestive signals produced by moxonidine injected into the LPBN. Male Sprague-Dawley rats were treated with FURO+CAP combined with bilateral injections of vehicle or moxonidine (0.5 nmol/0.2 μl) into the LPBN. Bilateral injections of moxonidine into the LPBN increased FURO+CAP-induced 1.8% NaCl intake, without changing water intake. Microstructural analysis of licking behavior found that this increase in NaCl intake was a function of increased number of licking bursts from 15 to 75 min of the test (maximum of 49±9 bursts/bin, vs. vehicle: 2±2 bursts/bin). Analysis of the first 15 min of the test, when most of the licking behavior occurred, found no effect of moxonidine on the number of licks/burst for sodium intake (24±5 licks/burst, vs. vehicle: 27±8 licks/burst). This finding suggests that activation of α2-adrenoceptors in the LPBN affects postingestive signals that are important to inhibit and limit sodium intake by FURO+CAP-treated rats.
authors.affiliation: Department of Physiology and Pathology, School of Dentistry, São Paulo State University (UNESP), Araraquara, Brazil.
authors.forename: S
authors.initials: S
authors.lastname: Gasparini
authors.affiliation: Department of Physiology and Pathology, School of Dentistry, São Paulo State University (UNESP), Araraquara, Brazil. Electronic address: menani@foar.unesp.br.
authors.forename: J V
authors.initials: JV
authors.lastname: Menani
authors.affiliation: Department of Psychology, University at Buffalo, The State University of New York, United States.
authors.forename: D
authors.initials: D
authors.lastname: Daniels
mesh_terms: D058647:Adrenergic alpha-2 Receptor Agonists / Q000494:pharmacology*; D000818:Animals; D002216:Captopril / Q000494:pharmacology; D002408:Catheters, Indwelling; D004232:Diuretics / Q000494:pharmacology; D004326:Drinking / Q000187:drug effects* / Q000502:physiology; D004327:Drinking Behavior / Q000187:drug effects* / Q000502:physiology; D060766:Drinking Water / Q000008:administration & dosage; D005665:Furosemide / Q000494:pharmacology; D007093:Imidazoles / Q000494:pharmacology*; D054755:Imidazoline Receptors / Q000819:agonists / Q000378:metabolism; D008297:Male; D065823:Parabrachial Nucleus / Q000187:drug effects* / Q000378:metabolism; D017207:Rats, Sprague-Dawley; D018341:Receptors, Adrenergic, alpha-2 / Q000378:metabolism; D012965:Sodium Chloride / Q000008:administration & dosage
chemical_list: D058647:Adrenergic alpha-2 Receptor Agonists; D004232:Diuretics; D060766:Drinking Water; D007093:Imidazoles; D054755:Imidazoline Receptors; D018341:Receptors, Adrenergic, alpha-2; D012965:Sodium Chloride; D005665:Furosemide; D002216:Captopril; C043482:moxonidine
keywords: parabrachial nucleus; postingestive; sodium intake; α(2)-adrenoreceptors