The nNOS/cGMP Mediation of the Depressor Response to NMDA Receptor Stimulation in the Caudal Ventrolateral Medulla

Wun-Chin Wu1 ； Chun-Kuei Su ； Ching-Yue Yang ； Chok-Yung Chai

《The Chinese Journal of Physiology》 46卷4期 (2003/12) Pp. 175-179

並列摘要

Using in vivo voltammetry to directly measure extracellular nitric oxide (NO) levels, our previous studies suggested that the neuronal NO synthase (nNOS) and cyclic guanosine monophosphate (cGMP) signal transducing systems are involved in the cardiovascular responses elicited by activation of Nmethyl- D-aspartate (NMDA) receptors in the rostral ventrolateral medulla. In this study, we examined if the depressor responses elicited by activation of NMDA receptors in the caudal ventrolateral medulla (CVLM) also depend on the actions of nNOS and soluble guanylyl cyclase. In anesthetized cats, microinjection of NMDA into the CVLM produced hypotension and bradycardia associated with NO formation. These NMDA-induced responses were attenuated by prior injections of 2-amino-5-phosphonopentanoate (a NMDA receptor competitive antagonist), 7-nitroindazole (a nNOS inhibitor) and 1H-[1,2,4]oxadiazolo[4,3-a]quinoxalin-1-one (an inhibitor of soluble guanylyl cyclase). These findings suggest that NO is also involved in the NMDA-induced depressor responses of the CVLM.

並列關鍵字

nitric oxide ； caudal ventrolateral medulla ； 7-nitroindazole ； 2-amino-5-phosphonopentanoate ； N-methyl-D-aspartate

參考文獻

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