Type 1 cannabinoid receptor modulates water deprivation-induced homeostatic responses

Autor(es)

Ruginsk, Silvia G. ^{[1, 2]} ; Vechiato, Fernanda M. V. ^[1] ; Uchoa, Ernane T. ^{[3, 1]} ; Elias, Lucila L. K. ^[1] ; Antunes-Rodrigues, Jose ^[1]

Afiliação do(s) autor(es)

^[1] Univ Sao Paulo, Sch Med Ribeirao Preto, Dept Physiol, Sao Paulo - Brazil

^[2] Univ Fed Alfenas, Inst Biomed Sci, Dept Physiol Sci, Alfenas, MG - Brazil

^[3] Univ Estadual Londrina, Dept Physiol Sci, Londrina, Parana - Brazil

• Tipo de documento: Artigo Científico
• Fonte: AMERICAN JOURNAL OF PHYSIOLOGY-REGULATORY INTEGRATIVE AND COMPARATIVE PHYSIOLOGY; v. 309, n. 11, p. R1358-R1368, DEC 1 2015.
• Citações Web of Science: 4

Resumo

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 CB(1)Rs 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 CB(1)Rs participate in the homeostatic responses regulating fluid balance and energy homeostasis during water deprivation. (AU)

• Processo FAPESP: 10/16692-0 - Avaliação da participação do receptor canabinóide do tipo CB1 nas respostas neuroendócrinas e sua possível interação com o sistema angiotensinérgico no modelo de privação hídrica.
• Beneficiário: Fernanda Maria Veanholi Vechiato
• Modalidade de apoio: Bolsas no Brasil - Iniciação Científica
• Processo FAPESP: 10/02748-4 - O apetite por água e sódio no modelo de privação hídrica: modulação pelo sistema endocanabinóide.
• Beneficiário: Silvia Graciela Ruginsk Leitão
• Modalidade de apoio: Bolsas no Brasil - Pós-Doutorado
• Processo FAPESP: 08/50611-8 - Regulação neuroendócrina do equilíbrio hidrossalino e da ingestão alimentar: aspectos fisiológicos, fisiopatológicos e moleculares
• Beneficiário: José Antunes Rodrigues
• Modalidade de apoio: Auxílio à Pesquisa - Temático