Anandamide modulates the neuroendocrine responses induced by extracellular volume expansion

Autor(es)

Ruginsk, Silvia G. ^[1] ; Uchoa, Ernane T. ^[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, BR-14049900 Sao Paulo - Brazil

• Tipo de documento: Artigo Científico
• Fonte: Clinical and experimental pharmacology & physiology; v. 40, n. 10, p. 698-705, OCT 2013.
• Citações Web of Science: 9

Resumo

The aim of the present study was to evaluate the effects of intracerebroventricular administration of anandamide (AEA), an inhibitor of fatty acid amide hydrolase activity (URB597) and a CB1 receptor (CB1R) antagonist (AM251) on the homeostatic responses elicited by extracellular volume expansion (EVE) in male adult rats. Pretreatment with AEA (100ng/4L) significantly reduced the effect of hypertonic (H-) EVE on plasma concentrations of prolactin (PRL), oxytocin (OT) and corticosterone, but not vasopressin (AVP). Administration of URB597 (20g/5L) alone significantly reduced PRL, OT, AVP and corticosterone in the H-EVE group. Conversely, URB597 and AEA had no significant effect on basal hormone concentrations. Pretreatment with AM251 (200ng/2L) potentiated OT but did not change AVP plasma levels in the H-EVE group. Hypertonic EVE significantly increased AVP and OT mRNA expression in the supraoptic nucleus (SON), an effect that was blunted in AEA-pretreated rats. Pretreatment with AEA did not change the percentage of vasopressinergic or oxytocinergic neurons colocalizing c-Fos in the SON, but increased nitrate concentrations in the median eminence of animals subjected to H-EVE. The present data suggest that: (i) vasopressinergic and oxytocinergic neurons may be differentially affected by AEA; (ii) activation of CB1R may restrain the response of the neurohypophyseal system (NHS) to EVE; (iii) the hypothalamic-pituitary-adrenal axis, PRL and the NHS may still be sensitive to AEA after EVE, with these effects probably not dependent on AEA metabolism; and (iv) AEA and nitric oxide could interact in vivo as modulators to directly control stress-induced responses. (AU)

• Processo FAPESP: 06/51938-5 - Efeitos do sistema canabinoide endogeno sobre a ativacao neuronal, sintese e secrecao hormonal em resposta a expansao isotonica e hipertonica do volume extracelular.
• Beneficiário: Silvia Graciela Ruginsk Leitão
• Modalidade de apoio: Bolsas no Brasil - Doutorado