title: Type 1 cannabinoid receptor modulates water deprivation-induced homeostatic responses.
abstract: The present study investigated the type 1 cannabinoid receptor (CB1R) as a potential candidate to mediate the homeostatic responses triggered by 24 h of water deprivation, which constitutes primarily a hydroelectrolytic challenge and also significantly impacts energy homeostasis. The present results demonstrated for the first time that CB1R mRNA expression is increased in the hypothalamus of water-deprived (WD) rats. Furthermore, the administration of ACEA, a CB1R selective agonist, potentiated WD-induced dipsogenic effect, whereas AM251, a CB1R antagonist, attenuated not only water but also salt intake in response to WD. In parallel with the modulation of thirst and salt appetite, we confirmed that CB1Rs are essential for the development of appropriated neuroendocrine responses. Although the administration of ACEA or AM251 did not produce any effects on WD-induced arginine vasopressin (AVP) secretion, oxytocin (OXT) plasma concentrations were significantly decreased in WD rats treated with ACEA. At the genomic level, ACEA significantly decreased AVP and OXT mRNA expression in the hypothalamus of WD rats, whereas AM251 potentiated both basal and WD-induced stimulatory effects on the transcription of AVP and OXT genes. In addition, we showed that water deprivation alone upregulated proopiomelanocortin, Agouti-related peptide, melanin-concentrating hormone, and orexin A mRNA levels in the hypothalamus, and that CB1Rs regulate main central peptidergic pathways controlling food intake, being that most of these effects were also significantly influenced by the hydration status. In conclusion, the present study demonstrated that CB1Rs participate in the homeostatic responses regulating fluid balance and energy homeostasis during water deprivation.
authors.affiliation: Department of Physiology, School of Medicine of Ribeirao Preto, University of São Paulo, Ribeirao Preto, São Paulo, Brazil; Department of Physiological Sciences, Biomedical Sciences Institute, Federal University of Alfenas, Alfenas, Minas Gerais, Brazil; and.
authors.forename: Silvia G
authors.initials: SG
authors.lastname: Ruginsk
authors.affiliation: Department of Physiology, School of Medicine of Ribeirao Preto, University of São Paulo, Ribeirao Preto, São Paulo, Brazil;
authors.forename: Fernanda M V
authors.initials: FM
authors.lastname: Vechiato
authors.affiliation: Department of Physiology, School of Medicine of Ribeirao Preto, University of São Paulo, Ribeirao Preto, São Paulo, Brazil; Department of Physiological Sciences, State University of Londrina, Londrina, Parana, Brazil.
authors.forename: Ernane T
authors.initials: ET
authors.lastname: Uchoa
authors.affiliation: Department of Physiology, School of Medicine of Ribeirao Preto, University of São Paulo, Ribeirao Preto, São Paulo, Brazil;
authors.forename: Lucila L K
authors.initials: LL
authors.lastname: Elias
authors.affiliation: Department of Physiology, School of Medicine of Ribeirao Preto, University of São Paulo, Ribeirao Preto, São Paulo, Brazil; jantunesr@gmail.com.
authors.forename: Jose
authors.identifier: http://orcid.org/0000-0002-6271-758X
authors.initials: J
authors.lastname: Antunes-Rodrigues
mesh_terms: D000818:Animals; D001069:Appetite Regulation; D001127:Arginine Vasopressin / Q000235:genetics / Q000378:metabolism; D062186:Arterial Pressure; D001522:Behavior, Animal; D063386:Cannabinoid Receptor Agonists / Q000494:pharmacology; D063387:Cannabinoid Receptor Antagonists / Q000494:pharmacology; D004734:Energy Metabolism / Q000187:drug effects; D005247:Feeding Behavior; D005786:Gene Expression Regulation; D007031:Hypothalamus / Q000187:drug effects / Q000378:metabolism*; D008297:Male; D023421:Models, Animal; D010121:Oxytocin / Q000235:genetics / Q000378:metabolism; D012333:RNA, Messenger / Q000378:metabolism; D017208:Rats, Wistar; D043884:Receptor, Cannabinoid, CB1 / Q000187:drug effects / Q000235:genetics / Q000378:metabolism*; D015398:Signal Transduction; D012964:Sodium / Q000097:blood; D017673:Sodium Chloride, Dietary / Q000008:administration & dosage; D013997:Time Factors; D014158:Transcription, Genetic; D014868:Water Deprivation; D014882:Water-Electrolyte Balance / Q000187:drug effects
chemical_list: D063386:Cannabinoid Receptor Agonists; D063387:Cannabinoid Receptor Antagonists; C543264:Cnr1 protein, rat; D012333:RNA, Messenger; D043884:Receptor, Cannabinoid, CB1; D017673:Sodium Chloride, Dietary; D001127:Arginine Vasopressin; D010121:Oxytocin; D012964:Sodium
keywords: ACEA; AM251; type 1 cannabinoid receptor; water deprivation