Microinjection of NMDA antagonist into the NTS of conscious rats blocks the Bezold-Jarisch reflex.

Carregando...
Imagem de Miniatura
Data
1996
Título da Revista
ISSN da Revista
Título de Volume
Editor
Resumo
The purpose of the present study was to evaluate whether or not cardiovagal excitatory and sympatho-inhibitory pathways of the Bezold-Jarischreflex at the NTS level were mediated by NMDA receptors. The Bezold-Jarischreflex was activated by intravenous (i.v.) injection of serotonin in consciousrats before and after microinjection of phosphonovaleric acid (AP-5), a selective NMDAantagonist, into the NTS. The Bezold-Jarischreflex was also activated before and after methyl-atropine (i.v.) in order to evaluate if the changes in mean arterial pressure were dependent on the bradycardic response. The data showed that AP-5 into the NTS produced a dose-dependent reduction in both bradycardic and hypotensive responses to activation of the Bezold-Jarischreflex. Methyl-atropine also blocked the bradycardic and hypotensive responses to Bezold-Jarischreflex activation. The data show that in consciousrats the cardiovagal component of the Bezold-Jarischreflex plays a major role in the cardiovascular changes produced by the activation of this reflex and suggest that the neurotransmission of the cardiovagal component of the Bezold-Jarischreflex is mediated by NMDA receptors.
Descrição
Palavras-chave
Phosphonovaleric acid, Sympatho-inhibition, Bradycardia, Cardiopulmonary receptor, Amino acid receptor
Citação
CHIANCA, JÚNIOR, D. A.; MACHADO, B. H. Microinjection of NMDA antagonist into the NTS of conscious rats blocks the Bezold-Jarisch reflex. Brain Research, v. 718, n. 1-2, p. 185-188, abr. 1996. Disponível em: <https://www.sciencedirect.com/science/article/pii/0006899396000108>. Acesso em: 26 nov. 2012.