Non-NMDA receptors within caudal ventrolateral medulla are involved in transmission of baroreflex of rats  

大鼠尾端延髓腹外侧区非NMDA受体参与压力反射传导(英文)

作　　者：王伟忠[1] 袁文俊[1] 潘燕霞[1] 白洁[1] 廖茂瑶[1] 唐朝枢[2] 

机构地区：[1]第二军医大学生理学教研室,上海200433 [2]北京大学医学部生理与病理生理学系

出　　处：《Acta Pharmacologica Sinica》2003年第8期783-789,共7页中国药理学报（英文版）

基　　金：Project supported by the Major State Basic Research Development Program of People's Republic of China (№ G2000056905);the Natural Science Foundation of China (№ 30070306)

摘　　要：AIM: To investigate the role of non N-methyl-D-aspartate acid (non-NMDA) receptors within the caudal ventrolateral medulla (CVLM) in mediating the baroreflex. METHODS: In urethane-anesthetized, paralyzed, and artificially ventilated rats, the effects of 6-cyano-7-nitroquinoxaline-2,3-dinoe (CNQX, a selective non-NMDA receptors antagonist) locally injected into the CVLM on the depressor responses evoked by aortic nerve stimulation and the barosensitivity of the rostral ventrolateral medulla (RVLM) barosensitive neurons were observed. RESULTS: Bilateral microinjection of CNQX (200 pmol in 100 nL for each side) into the CVLM significantly (P<0.01) increased the blood pressure (BP) and heart rate, and markedly (P<0.01) attenuated the depressor response to the aortic nerve stimulation. CNQX (200 pmol in 100 nL) unilaterally injected into the CVLM significantly (P<0.01) increased the firing rate of the ispilateral RVLM barosensitive neurons and reduced the inhibitory responses of neurons evoked by stimulation of aortic nerve and elevation of BP, and partially inhibited the neuronal cardiac cycle-related rhythm. CONCLUSION: The CVLM played an important role in maintaining the tonic excitatory cardiovascular activities and transmitting the baroreceptor information via activation of non-NMDA receptors.目的:探讨大鼠尾端延髓腹外侧区(CVLM)非N-甲基-D-天门冬氨酸(non-NMDA)受体在介导压力反射中的作用。方法:在戊巴比妥钠和氨基甲酸乙酯麻醉、制动和人工呼吸的SD大鼠,观察CVLM内局部给予non-NMDA受体选择性阻断剂CNQX对刺激主动脉神经导致的减压反应和头端延髓腹外侧区(RVLM)神经元的压力敏感性的作用。结果:双侧CVLM微量注射CNQX(每侧200 pmol/100 nL)后明显(P<0.01)地增高基础血压(BP)和心率,而且显著(P<0.01)地减弱刺激主动脉神经导致的降压反应。单侧CVLM内给予CNQX(200 pmol/100 nL)明显(P<0.01)增高同侧RVLM压力敏感性神经元的基础放电频率,但显著(P<0.01)减弱刺激主动脉神经和升高血压导致的神经元活动的抑制效应和部分抑制神经元的心性节律。结论:大鼠尾端延髓腹外侧区non-NMDA受体在维持紧张性兴奋的心血管活动和传递压力感受器信息中具有重要的意义。

关 键 词：glutamate receptors BAROREFLEX blood pressure medulla oblongata 

分 类 号：R338[医药卫生—人体生理学]