Purinergic and glutamatergic interactions in the hypothalamic paraventricular nucleus modulate sympathetic outflow

Autor(es)

Ferreira-Neto, H. C. ^[1] ; Yao, S. T. ^[2] ; Antunes, V. R. ^[1]

Afiliação do(s) autor(es)

^[1] Univ Sao Paulo, Inst Biomed Sci, Dept Physiol & Biophys, Sao Paulo - Brazil

^[2] Univ Melbourne, Florey Inst Neurosci & Mental Hlth, Melbourne, Vic - Australia

• Tipo de documento: Artigo Científico
• Fonte: PURINERGIC SIGNALLING; v. 9, n. 3, p. 337-349, SEP 2013.
• Citações Web of Science: 6

Resumo

P2X receptors are expressed on ventrolateral medulla projecting paraventricular nucleus (PVN) neurons. Here, we investigate the role of adenosine 5'-triphosphate (ATP) in modulating sympathetic nerve activity (SNA) at the level of the PVN. We used an in situ arterially perfused rat preparation to determine the effect of P2 receptor activation and the putative interaction between purinergic and glutamatergic neurotransmitter systems within the PVN on lumbar SNA (LSNA). Unilateral microinjection of ATP into the PVN induced a dose-related increase in the LSNA (1 nmol: 38 +/- 6 %, 2.5 nmol: 72 +/- 7 %, 5 nmol: 96 +/- 13 %). This increase was significantly attenuated by blockade of P2 receptors (pyridoxalphosphate-6-azophenyl-20,40-disulphonic acid, PPADS) and glutamate receptors (kynurenic acid, KYN) or a combination of both. The increase in LSNA elicited by L-glutamate microinjection into the PVN was not affected by a previous injection of PPADS. Selective blockade of non-N-methyl-D-aspartate receptors (6-cyano-7-nitroquinoxaline-2,3-dione disodium salt, CNQX), but not N-methyl-D-aspartate receptors (NMDA) receptors (DL-2-amino-5-phosphonopentanoic acid, AP5), attenuated the ATP-induced sympathoexcitatory effects at the PVN level. Taken together, our data show that purinergic neurotransmission within the PVN is involved in the control of SNA via P2 receptor activation. Moreover, we show an interaction between P2 receptors and non-NMDA glutamate receptors in the PVN suggesting that these functional interactions might be important in the regulation of sympathetic outflow. (AU)

• Processo FAPESP: 07/04085-0 - Análise funcional de genes relacionados à hipertensão neurogênica
• Beneficiário: Vagner Roberto Antunes
• Modalidade de apoio: Auxílio à Pesquisa - Regular
• Processo FAPESP: 10/05037-1 - Papel dos receptores purinérgicos do núcleo paraventricular do hipotálamo na hipertensão neurogênica
• Beneficiário: Hildebrando Candido Ferreira Neto
• Modalidade de apoio: Bolsas no Brasil - Doutorado
• Processo FAPESP: 10/17997-0 - Mecanismos da neurotransmissão purinérgica do hipotálamo sobre a atividade autonômica simpática e sua relação com a hipertensão neurogênica
• Beneficiário: Vagner Roberto Antunes
• Modalidade de apoio: Auxílio à Pesquisa - Regular