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家兔杏仁核内的5-羟色胺和内源性吗啡样物质在电针镇痛和吗啡镇痛中起重要作用

许德义, 周仲福, 韩济生

新疆石河子医学院. 新疆；北京医学院生理教研室. 北京

摘要

该工作的目的是要确定杏仁核内的吗啡样物质(内啡素)和5-羟色胺(5-HT)是否参与电针镇痛和吗啡镇痛。经慢性埋植套管向家兔杏仁核内微量注射阿片受体阻断剂纳洛酮,或5-HT受体阻断剂肉桂硫胺,可使电针的镇痛效果显著减弱,尤以注入中央杏仁核作用最为显著,双侧注射效果大于单侧,注入核外则无效。杏仁核内注入5-HT 的前体5-HTP,或脑啡肽降解酶抑制剂 D-苯丙氨酸可使电针镇痛显著加强。上述措施凡是加强或对抗电针镇痛的,也能加强或对抗吗啡镇痛。以上结果表明,电针刺激或注射吗啡可能在杏仁核内引起5-HT 和内啡素(很可能是脑啡肽)的释放,而发挥镇痛效应。

关键词： 杏仁核; 5-羟色胺; 内源性吗啡样物质; 电针镇痛; 吗啡镇痛; 家兔

Amygdaloid serotonin and endogenous opioid substances (ols) are important for mediating electroacupuncture analgesia and morphine analgesia in the rabbit

Xu Deyi, Zhou Zhongfu, Han Jisheng

Department of Physiology, Beijing Medical College. Beijing, China

Abstract

The purpose of this study was to determine whether serotonin (5-HT) and endogenous opioid substances (OLS) contained and released in amygdala play a rolein mediating the analgesic effect elicited by morphine or electroacupuncture (EA) stimulation. Rabbits were equipped with bilateral stainless steel guide cannulae (o. d. 0.7 mm) with the cannula tip placed dorsal to the amygdala. Microinjection was performed through an injection tube (o. d. 0.3 mm) protruding 2 mm beyond the cannula tip to reach the nucleus, at a speed of 2 #mu#l/8 min. Pain threshold was assessed by the latency of radiant heat head jerk response. (1) Pain threshold was significantly increased by bilateral intra-amygdaloid injection of morphine (10 #mu#g/site), but not by normal saline, naloxone (2 #mu#g/site), cinanserin (4 #mu#g/site), D-phenylalanine (DPA, 10 #mu#g/site)or 5-hydroxytryptophan (5-HTP, 2.5 #mu#g/site). (2) The analgesic effect induced by EA stimulation was significantly attenuated by the intra-amygdaloid injection of opiate receptor blocker naloxone or 5-HT receptor blocker cinanserin. Maximal blocking effect was obtained by bilateral intra-amygdaloid injection, especially to the central nucleus of amygdala. Unilateral injection elicited a weaker action. Injection to the vicinity of amygdala was not effective (3) EA analgesia was significantly augmented by intra-amygdaloid injection of 5-HTP (a precursor of 5-HT) or of DPA (a putative blocking agent for enkephalin degradating enzymes). (4) Chemical agents exerting a potentiating or antagonizing effect on EA analgesia showed a similar effect on morphine analgesia in the same site of injection. The results suggest that morphine and EA may stimulate the release of 5-HT and OLS (most probably enkephalins) in the amygdala thereby producing an analgesic effect.

Key words: Amygdala;Serotonin;Endogenous opioid substances;Electroacupuncture analgesia;Morphine analgesia;Rabbit

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引用本文：

许德义, 周仲福, 韩济生. 家兔杏仁核内的5-羟色胺和内源性吗啡样物质在电针镇痛和吗啡镇痛中起重要作用[J]. 生理学报 1985; 37 (2): .

Xu Deyi, Zhou Zhongfu, Han Jisheng. Amygdaloid serotonin and endogenous opioid substances (ols) are important for mediating electroacupuncture analgesia and morphine analgesia in the rabbit. Acta Physiol Sin 1985; 37 (2): (in Chinese with English abstract).