Effect of antagonism of glutamate receptors in the PVN region on baroreflex in conscious rats / 中国应用生理学杂志

ABSTRACT

<p><b>AIM</b>To investigate the possible involvement of glutamate(Glu) in the paraventricular nucleus (PVN) in the central regulation of baroreflex.</p><p><b>METHODS</b>The baroreflex was induced by intravenous injection of phenylephrine in conscious rats, and the extracellular concentration of Glu in the PVN region was measured by microdialysis and high performance liquid chromatography (HPLC) techniques. To determine whether the observed Glu release was involved in the baroreflex, NMDA and non-NMDA receptor antagonists, MK-801 and CNQX, were perfused in the PVN region during baroreflex.</p><p><b>RESULTS</b>During baroreflex, the Glu concentration in the PVN region immediately increased to 384.82% +/- 91.77% of basal level (P < 0.01). (2) During baroreflex, direct perfusion of MK-801 and CNQX in the PVN were attenuated the increase of blood pressure and enhanced the decrease of HR (P < 0.01),resulting a significant increase in baroreflex sensitivity (P < 0.01).</p><p><b>CONCLUSION</b>Glutamate in PVN is involved in central regulation of baroreflex, which may inhibit baroreflex via ionothopic glutamate receptors.</p>