L－NNA及NO供体对延髓腹外侧头端区神经元自发放电的影响  

EFFECTS OF L-NNA AND NO DONORS ON SPONTANEOUS ACTIVITY OF ROSTRAL VENTROLATERAL MEDULLA NEURONS

作　　者：杨丽明[1] 何瑞荣[1] 

机构地区：[1]河北医科大学基础医学研究所生理室,北京中国协和医科大学,北京中国医学科学院,北京基础医学研究所病理生理研究室

出　　处：《生理学报》1996年第4期320-328,共9页Acta Physiologica Sinica

摘　　要：在麻醉大鼠观察了静注ＮＯ合成酶抑制剂Ｎ－硝基左旋精氨酸（Ｌ－ＮＮＡ）和ＮＯ供体──硝普钠（ＳＮＰ）和ＳＩＮ－Ｉ对血压、心率和延髓腹外侧头端区（ＲＶＬＭ）神经元自发放电活动的影响，旨在探讨Ｌ－ａｒｇ：ＮＯ通路对动脉血压调节的中枢作用部位。所得结果如下：（１）静注Ｌ－ＮＮＡ后，平均动脉压（ＭＡＰ）升高，心率（ＨＲ）加快，１１个ＲＶＬＭ神经元自发放电频率增加。这些变化发生于给药后５ｍｉｎ，持续时间达３０ｍｉｎ以上。（２）静注ＳＮＰ后，ＭＡＰ降低，ＨＲ加快，２３个ＲＶＬＭ神经元自发放电频率降低，且有剂量依赖性。ＳＮＰ作用发生快，持续时间短。为了排除脑缺血的影响，还特意向一侧颈动脉内注射相同剂量ＳＮＰ，结果引起ＭＡＰ轻度降低，而ＨＲ无明显改变，但ＲＶＬＭ神经元自发放电频率仍显著降低。（３）静注另一ＮＯ供体ＳＩＮ－Ｉ后，ＭＡＰ降低，１１个ＲＶＬＭ神经元自发放电频率降低．与ＳＮＰ的效应基本一致。以上结果提示，ＲＶＬＭ是Ｌ－ａｒｇ：ＮＯ通路实现动脉血压调节的一个中枢作用部位。The effects of intravenous injection of a NO synthase inhibitor ──N-nitro-Larginine (L-NNA) and NO donors ──sodium nitroprusside (SNP) and SIN-I on blood pressure (BP), heart rate (HR) and spontaneous activity of rostral ventrolateral medulla (RVLM) neurons were examined in 22 anesthetized rats to define the action site of L-arginine: NO pathway in BP regulation. The results obtained were as follows.(1) Following i. v. injection of L-NNA, mean artery pressure (MAP), HR and spentaneons discharge rate of 14 RVLM neurons were all increased, all effects starting at 5 min after administration of L-NNA and lasting for more than 30 min. (2) In response to i. v. injection of SNP, MAP was decreased with concomitant increase in HR and the discharge rate of 23 RVLM neurons decreased in a dose-dependent manner. These effeets were rapid in onset and also disappeared promptly. To exclude the effect of cerebral ischemia induced by decreased of BP, the effects of intracarotid injection of SNP were examined. Following i. a. injection, MAP was only slightly decreased and HR showed no significant change, but the discharge rate of 1 4 RVLM neurons was significantly decreased. (3) During i. v. injection of another NO donor ──SIN-I, MAP and the spontaneous discharge rate of 11 RVLM neurons were decreased. The above results indicate that the L-arginine: NO pathway may exert a modulatory action on the blood pressure through rostral ventrolateral medulla.

关 键 词：延髓腹外侧 头端区 一氧化氮 硝基左旋精氨酸 

分 类 号：R338.22[医药卫生—人体生理学]