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(Referência obtida automaticamente do Web of Science, por meio da informação sobre o financiamento pela FAPESP e o número do processo correspondente, incluída na publicação pelos autores.)

HYPOTHALAMIC COCAINE- AND AMPHETAMINE-REGULATED TRANSCRIPT AND CORTICOTROPHIN RELEASING FACTOR NEURONS ARE STIMULATED BY EXTRACELLULAR VOLUME AND OSMOTIC CHANGES

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Autor(es):
Ruginsk, S. G. [1] ; Uchoa, E. T. [1] ; Elias, L. L. K. [1] ; Antunes-Rodrigues, J. [1] ; Llewellyn-Smith, I. J. [2]
Número total de Autores: 5
Afiliação do(s) autor(es):
[1] Univ Sao Paulo, Dept Fisiol, Fac Med Ribeirao Preto, BR-14049900 Sao Paulo - Brazil
[2] Flinders Univ S Australia, Ctr Neurosci, Bedford Pk, SA 5042 - Australia
Número total de Afiliações: 2
Tipo de documento: Artigo Científico
Fonte: Neuroscience; v. 186, p. 57-64, JUN 14 2011.
Citações Web of Science: 10
Resumo

Several studies suggest that hypothalamic cocaine- and amphetamine-regulated transcript (CART) may interact with the hypothalamic-pituitary-adrenal (HPA) axis in the control of neuroendocrine function and may also participate in cardiovascular regulation. Therefore, this study aimed to evaluate, in experimental models of isotonic (I-EVE) and hypertonic (H-EVE) extracellular volume expansion and water deprivation (WD), the activation of CART- and corticotrophin releasing factor (CRF)-immunoreactive neurons, as well as the relative expression of CART and CRF mRNAs in the paraventricular (PVN) and supraoptic (SON) nuclei of the hypothalamus. Both H-EVE (0.30M NaCl, 2mL/100g of body weight, in 1 minute) and 24 hours of WD significantly increased plasma sodium concentrations, producing, respectively, either an increase or a decrease in extracellular volume. I-EVE (0.15M NaCl, 2mL/100g of body weight, in 1 minute) evoked a significant increase in the circulating volume accompanied by unaltered plasma concentrations of sodium. CART-expressing neurons of both magnocellular and parvocellular hypothalamic divisions were activated to produce Fos in response to H-EVE but not in response to I-EVE. Furthermore, increased expression of CART mRNA was found in the PVN of H-EVE but not I-EVE rats. These data show for the first time that EVE not only activates hypothalamic CRF neurons but also increases CRF mRNA expression in the PVN. In contrast, WD increases the number of CART-immunoreactive neurons activated to produce Fos in the PVN and SON but does not change the number of neurons double labeled for Fos and CRF or expression of CRF mRNA in the PVN. These findings provided new insights into the participation of CART in diverse processes within the PVN and SON, including its possible involvement in activation of the HPA axis and cardiovascular regulation in response to changes in extracellular volume and osmolality. (C) 2011 IBRO. Published by Elsevier Ltd. All rights reserved. (AU)

Processo FAPESP: 06/51938-5 - Efeitos do sistema canabinóide endógeno sobre a ativação neuronal, síntese e secreção hormonal em resposta a expansão isotônica e hipertônica do volume extracelular
Beneficiário:Silvia Graciela Ruginsk Leitão
Linha de fomento: Bolsas no Brasil - Doutorado
Processo FAPESP: 03/00327-8 - Estudo integrado do equilíbrio hidrossalino: aspectos fisiológicos e moleculares da regulação neuroendócrina e avaliação de aspectos clínicos e experimentais
Beneficiário:José Antunes Rodrigues
Linha de fomento: Auxílio à Pesquisa - Temático