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NO前体和供体对大鼠海马脑片神经元活动的影响

薛保建, 王志安, 何瑞荣

(河北医科大学基础医学研究所生理室，石家庄050017)

摘要

应用细胞外记录单位放电技术，在大鼠海马脑片上观察了左旋精氨酸(L-arg), N一硝基左旋精氨酸(L-NNA), SIN-1、及亚甲基蓝(methylene blue, MB)对CA1区神经元自发放电的影响，旨在了解左旋精氨酸:NO通路在海马放电中的作用及其可能的机制。实验结果如下:(1)用Larg (1 mmol/L)灌流海马脑片2 min，在54个放电单位中有42个单位(77.800)放电频率降低,12个单位(22.200)无明显反应。用L-NNA (0. 15 mmol/L)灌流海马脑片2 min，在29个放电单位中有25个单位(86.2086.2%)放电频率增加，4个单位(13.8%)无明显变化。L-NNA的作用可被预先灌流L-Arg而逆转。(2)给予一氧化氮(NO)供体SIN-1 (5 mmol/L)飞25个单位(10000)放电频率均明显减少，呈明显的剂量依赖性。(3)给脑片灌流鸟昔酸环化酶抑制剂亚甲基蓝((3umol/L) 30 min后，10个单位的平均放电频率较对照时明显增加，但亚甲基蓝不能消除L-arg对海马神经元的作用。综合上述结果，似可以认为，静息的海马有基础性NO释放，NO可抑制海马的放电活动，其作用似不通过鸟昔酸环化酶介导。

关键词： 一氧化氮(NO); 海马脑片; 亚甲基蓝

EFFECTS OF NO PRECURSOR AND DONOR ON NEURONAL ACTIVITY OF RAT HIPPOCAMPAL SLICES

XUE BAO-JIAN, WANG ZHI-AN, HE RUI-RONG (HO SHIU_YONG)

(Department of Physiology, Institute of Basic Medicine, Hebei Medical University, Shijiazlnurng 050017)

Abstract

Using extracellular recording technique，the effects of L-arginine (L-arg)，N-nitro-L-arginine (L-NNA)，SIN-1 and methylene blue (MB) on spontaneous discharges of neurons in CAI area of hippocampal slices were examined to determine the role of Larg:NO pathway and the possible underlying mechanism. The results were as follows:(1)In response to the application of L-arg(1 mmol/L) into the superfusate for 2 minspontaneous discharge rate (SDR)of 42/54(77. 8%)neurons was decreased significantly，while that of 12/54(22. 2%)neurons showed no change. Following the application of L-NNA(0. 15 mmol/L)into the superfusate for 2 min，SDR of 25/ 29(86.2%)neurons was increased markedly and that of 4/29(13.8%)neurons was not affected. The effect of L-NNA might be reversed by pretreatment with L-arg.(2) With application of NO donor SIN一1(5 mmol/L)，SDR of 25(100%)neurons was decreased in a dose-dependent manner.(3) After superfusing the brain slice with guanylate cyclase inhibitor，MB(3 pmol/L) for 30 min，SDR of 10 units showed significant increase as compared with control. However，MB failed to abolish the effect of L-arg on hippocampal neurons. Taken together，it is likely that NO is released during the resting state of hippocampal neurons and may inhibit the activity of hippocampus，
an effect not mediated by the action of euanvlate cvclase.

Key words: nitric oxide;Hippocampal slices;methylene blue

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引用本文：

薛保建, 王志安, 何瑞荣. NO前体和供体对大鼠海马脑片神经元活动的影响[J]. 生理学报 1997; 49 (4): .

XUE BAO-JIAN, WANG ZHI-AN, HE RUI-RONG (HO SHIU_YONG). EFFECTS OF NO PRECURSOR AND DONOR ON NEURONAL ACTIVITY OF RAT HIPPOCAMPAL SLICES. Acta Physiol Sin 1997; 49 (4): (in Chinese with English abstract).