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

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Data
1996
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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.
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Phosphonovaleric acid, Sympatho-inhibition, Bradycardia, Cardiopulmonary receptor, Amino acid receptor
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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.