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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

杨丽明, 何瑞荣

河北医科大学基础医学研究所生理室，石家庄。5。。}7)

摘要

在麻醉大鼠观察了静注NO合成酶抑制剂N一硝基左旋精氨酸((L-NNA)和NO供体—硝普
钠(SNP)和SIN-1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，14个RVLM神经元自发放电频率增加。这些变化发
生于给药后5 min，持续时间达30 min以f=o (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，待续时问短。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--- NO供体SIN一工后，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。以匕结果提示， RVLM是L-arg, NO通路实现动脉血压调节的一个中枢作用部位。

关键词： 延髓腹外侧头端区; 一氧化氮; N一硝基左旋精氨酸; 硝普钠; SIN-1; 心血管活动调节

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

YANG LI-MING , HE RUI-RONG (HO SHIU-YONG

(Department of Physiology, Institute of Bxsie Medicine, Hebei Medical University, Shijiazhuarag 050017)

Abstract

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 spontaneous discharge rate of 14 RVLM neurons were all increased，all effects starting at 5min 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 effects 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 signify cantly decreased.(3)During i. v. injection of another NO donor—SIN一I，MAP and the spontaneous discharge rate of I 1 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.

Key words: Rostral ventrolateral medulla;N-nitro-L-arginine; SIN-I;cardiovascular regulation ;;

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引用本文：

杨丽明, 何瑞荣. 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[J]. 生理学报 1996; 48 (4): .

YANG LI-MING , HE RUI-RONG (HO SHIU-YONG. EFFECTS OF L-NNA AND NO DONORS ON SPONTANEOUS ACTIVITY OF ROSTRAL VENTROLATERAL MEDULLA NEURONS. Acta Physiol Sin 1996; 48 (4): (in Chinese with English abstract).