Cardiovascular responses to glutamate microinjection in the dorsomedial periaqueductal gray of unanesthetized rats

Autor(es)

Pelosi, Gislaine Garcia ^{[1, 2]} ; Busnardo, Cristiane ^[1] ; Tavares, Rodrigo Fiacadori ^[1] ; Aguiar Correa, Fernando Morgan ^[1]

Afiliação do(s) autor(es)

^[1] Univ Sao Paulo, Sch Med Ribeirao Preto, Dept Pharmacol, Sao Paulo - Brazil

^[2] Univ Estadual Londrina, Dept Ciencias Fisiol, Ctr Biol Sci, BR-86055900 Londrina, Parana - Brazil

• Tipo de documento: Artigo Científico
• Fonte: Journal of Neuroscience Research; v. 90, n. 11, p. 2193-2200, NOV 2012.
• Citações Web of Science: 8

Resumo

The periaqueductal gray area (PAG) is a mesencephalic area involved in cardiovascular modulation. Glutamate (L-Glu) is an abundant excitatory amino acid in the central nervous system (CNS) and is present in the rat PAG. Moreover, data in the literature indicate its involvement in central blood pressure control. Here we report on the cardiovascular effects caused by microinjection of L-Glu into the dorsomedial PAG (dmPAG) of rats and the glutamatergic receptors as well as the peripheral mechanism involved in their mediation. The microinjection of L-Glu into the dmPAG of unanesthetized rats evoked dose-related pressor and bradycardiac responses. The cardiovascular response was significantly reduced by pretreatment of the dmPAG with a glutamatergic M-methyl-D-aspartate (NMDA) receptor antagonist (LY235959) and was not affected by pretreatment with a non-NMDA receptor antagonist (NBQX), suggesting a mediation of that response by the activation of NMDA receptors. Furthermore, the pressor response was blocked by pretreatment with the ganglion blocker pentolinium (5 mg/kg, intravenously), suggesting an involvement of the sympathetic nervous system in this response. Our results indicate that the microinjection of L-Glu into the dmPAG causes sympathetic-mediated pressor responses in unanesthetized rats, which are mediated by glutamatergic NMDA receptors in the dmPAG. (c) 2012 Wiley Periodicals, Inc. (AU)

• Processo FAPESP: 05/57227-0 - Estudo dos efeitos cardiovasculares e comportamentais da microinjeção de noradrenalina na substância cinzenta periaquedutal de ratos
• Beneficiário: Gislaine Garcia Pelosi Gomes
• Linha de fomento: Bolsas no Brasil - Pós-Doutorado
• Processo FAPESP: 09/05308-8 - Função do núcleo paraventricular do hipotálamo na resposta cardiovascular e neuroendócrina observada em ratos submetidos ao estresse por restrição
• Beneficiário: Cristiane Busnardo Santiago
• Linha de fomento: Bolsas no Brasil - Pós-Doutorado