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大鼠脊髓中的去甲肾上腺素在吗啡镇痛中的作用

谢翠微, 杜晓立, 汤健, 韩济生

北京医学院生理教研室. 北京

摘要

该文报道中枢去甲肾上腺素(NE)能下行系统的脊髓末梢以及脊髓内的α受体在吗啡镇痛机制中的作用。结果显示,皮下注射6mg/kg 吗啡可使脊髓中的 NE 代谢终产物3-甲氧基4-羟基苯乙二醇硫酸盐(MHPG·SO_(4))含量升高,提示脊髓 NE 的更新加速;反复多次注射吗啡引起吗啡镇痛耐受的动物,该反应消失。脊髓蛛网膜下腔注射α受体阻断剂酚妥拉明可部分对抗全身注射小剂量吗啡的镇痛作用,选择性的α_(1)受体阻断剂哌唑嗪或α_(2)受体阻断剂育亨宾有类似作用。阻断脊髓α_1或α_2受体对脊髓蛛网膜下腔直接注射微量吗啡的镇痛作用无显著影响,以上结果表明,下行 NE 能系统在吗啡镇痛机制中具有重要作用。

关键词： 去甲肾上腺素; 3-甲氧基4-羟基苯乙二醇硫酸盐; 吗啡镇痛; 吗啡耐受; α受体阻断剂; 脊髓蛛网膜下腔注射

Participation of spinal norepinephrine in morphine analgesia in rats

Xie Cuiwei, Du Xiaoli, Tang Jian, Han Jisheng

Department of Physiology, Beijing Medical College. Beijing, China

Abstract

The present study was performed in an attempt to define the involvement of descending noradrenergic pathway and the spinal a-adrenoceptors in the mechanisms of morphine analgesia. It was found that acute morphine treatment (6mg/kg, sc) increased the spinal content of 3-methoxy-4-hydroxyphenylglycol sulfate (MHPG·SO_(4)), a metabolic end-product of central norepinephrine (NE),thus suggesting an increased NE turn-over. This response was no longer present in animals made tolerant to morphine analgesia by chronic morphine treatment. Different kinds of a-adrenoceptor antagonists were injected intrathecally to assess their effects on morphine analgesia. While analgesia produced by a small dose of systemic morphine was attenuated by phentolamine, as well as by selective #alpha#_(1) or #alpha#_(2)-blocker, prazosin or yohimbine, analgesia induced by intrathecal morphine was not affected by prazosin or yohimbine. These findings indicate that descending noradrenergic system from supcaspinal structures may serve as one of the important mechanisms for morpine analgesia.

Key words: Norepanephrine;MHPG·SO_(4);Morphine analgesia;Morphine tolerance;Alpha-adrenoceptor antagonist;Intrathecal injection

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引用本文：

谢翠微, 杜晓立, 汤健, 韩济生. 大鼠脊髓中的去甲肾上腺素在吗啡镇痛中的作用[J]. 生理学报 1985; 37 (3): .

Xie Cuiwei, Du Xiaoli, Tang Jian, Han Jisheng. Participation of spinal norepinephrine in morphine analgesia in rats. Acta Physiol Sin 1985; 37 (3): (in Chinese with English abstract).