Autonomic processing of the cardiovascular reflexes in the nucleus tractus solitarii
Braz. j. med. biol. res
;
30(4): 533-43, Apr. 1997.
Article
Dans Anglais
| LILACS
| ID: lil-191391
RESUMO
The nucleus tractus solitarii (NTS) receives afferent projections from the arterial baroreceptors, carotid chemoreceptors and cardiopulmonary receptors and as a function of this information produces autonomic adjustments in order to maintain arterial blood pressure within a narrow range of variation.The activation of each of these cardiovascular afferents produces a specific autonomic response by the excitation of neuronal projections from the NTS to the ventrolateral areas of the medulla (nucleus ambiguus, caudal and rostral ventrolateral medulla). The neurotransmitters at the NTS level as well as the excitatory amino acid (EAA) receptors involved in the processing of the autonomic responses in the NTS, although extensively studied, remain to be completely elucidated. In the present review we discuss the role of the EAA L-glutamate and its different receptor subtypes in the processing of the cardiovascular reflexes in the NTS. The data presented in this review related to the neurotransmission in the NTS are based on experimental evidence obtained in our laboratory in unanesthetized rats. The two major conclusions of the present review are that a) the excitation of the cardiovagal component by cardiovascular relfex activation (chemo- and Bezold-Jarisch reflexes) or by L-glutamatae microinjection into the NTS is mediated by N-methyl-D-aspartate (NMDA) receptors, and b) the sympatho-excitatory componente of the chemoreflex and the pressor response to L-glutamate microinjected into the NTS are not affected by an NMDA receptor antagonist, suggesting that the sympatho-excitatory component of these responses is mediated by non-NMDA receptors.
Texte intégral:
Disponible
Indice:
LILAS (Amériques)
Sujet Principal:
Cyanure de potassium
/
Barorécepteurs
/
Réflexe
/
Système cardiovasculaire
/
Sérotonine
/
Cellules chimioréceptrices
/
Récepteurs au glutamate
/
Noyau du tractus solitaire
/
Acide glutamique
/
Glycine
Limites du sujet:
Animaux
langue:
Anglais
Texte intégral:
Braz. j. med. biol. res
Thème du journal:
Biologie
/
Médicament
Année:
1997
Type:
Article
/
Congrès et conférence
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