Arcuate nucleus of hypothalamus involved in analgesic action of l-THP  

下丘脑弓状核参与左旋四氢巴马汀的镇痛作用(英文)

作　　者：胡江元[1] 金国章 

机构地区：[1]中国科学院上海药物研究所

出　　处：《Acta Pharmacologica Sinica》2000年第5期57-62,共6页中国药理学报（英文版）

基　　金：Supported by the National Natural Science Foundation of China, № 39770853 and 39670829.

摘　　要：AIM: To study the role of the arcuate nucleus of hy-pothalamus in analgesic action of l-tetrahydropalmatine (l-THP). METHODS: The horseradish peroxidase (HRP) retrograde tracing, HRP retrograde tracing combined with immunohistochemistry, lesion of nucleus, tail-flick test, and intra-PAG injection were used in the present study. RESULTS: HRP retrograde tracing results showed that the striatum or accumbens nucleus connect with PAG by two pathways: 1) striatum or accumbens nucleus→arcuate nucleus→PAG; 2) striatum or accumbens nucleus→habenula→PAG. It was found that neurons in the arcuate nucleus projecting to PAG were mainly β-endorphin neurons as observed by HRP retrograde tracing combined with immuno-histochemistry. After lesion of the arcuate nucleus, the analgesic action of l-THP (40 rng·kg-1, ip) was abolished, while lesion of the habenula had no such effect. Moreover, intra-PAG injection of naloxone (2, 3μg) could markedly attenuate the analgesic action of l-THP (40 mg·kg-1, ip) in a dose-dependent manner. CONCLUSION: β-Endorphin neurons in the arcuate nucleus play an important role in the analgesic action of l-THP.目的:研究弓状核在左旋四氢巴马汀(l-THP)镇痛效应中的作用,以阐明l-THP的镇痛作用机制。方法:应用辣根过氧化物酶(HRP)逆行追踪术追踪纹状体或伏膈核与PAG之间的纤维联系,HRP逆行追踪结合免疫组化观察投射神经元的性质,神经核团损毁和PAG核内注射药物观察对l-THP镇痛作用的影响。结果:纹状体或伏膈核通过弓状核或缰核间接与PAG联系,弓状核投射至PAG的神经元大部分是β内啡肽神经元。损毁弓状核后,l-THP的镇痛作用消失,而损毁缰核对l-THP的镇痛作用无明显影响。PAG核内注射纳洛酮能剂量依赖性翻转l-THP的镇痛作用。结论:弓状核的β内啡肽神经元在l-THP镇痛作用中起重要作用。

关 键 词：TETRAHYDROPALMATINE horseradish perox-idase arcuate nucleus PAG corpus striatum nucleus accumbens analgesia NALOXONE ENDORPHINS 

分 类 号：R96[医药卫生—药理学]