中枢5-HT_1受体介导的降压效应及其机制

HYPOTENSIVE EFFECT AND ITS MECHANISMS INDUCED BY CNS 5-HT_1 RECEPTOR

目的：观察5－HT1受体介导的降压反应，方法：采用大鼠侧脑室注射5－HT1受体激动剂m－cpp；蛛网膜下腔注射α受体阻断剂Regitin或阿片肽受体阻断剂Naloxone，切断双侧颈迷走神经。测定其平均动脉压（mABP）和HR的变化。结果：侧脑室注射m－cpp引起明显降压效应，但心率无明显变化；蛛网膜下腔注射regitin和naloxone可翻转和部分翻转m－cpp所致的降压作用；切除双侧颈迷走神经不影响m－cpp所致的降压作用。结论：m－cpp有明显降压作用，其降压效应中有去甲肾上腺素系统和阿片肽能纤维的参与，与副交感神经的活动无关。

objective: To observe the hypotensive effect and its mechanisms induced by CNS 5-HT1 receptor Methods: The changes of the mean arterial blood pressure (mABP) and heart' rate (HR) were measured after intrathecal (ith) administration of regitin and naloxone to anaesthesized rats as well as after bilateral carotid vagotomy.Results: A marked dose-dependent hypotensive effect was preduced by i. c.v. injection of m-cpp, a 5-HT1 receptor agonist. The hypotensive effect of m-cpp cou1d be reversed by ith administration of regitin, and antagonist of α-receptor, and parly reversed by naloxone, an antagonist of opioid receptor, but could not be reversed by bilateral carotid vagotomy. Conclusion: m-cpp exerts a powerful central hypotensive effect in which noradrenaline system and opiopeptidergic fibers participate whereas parasympathetic fiberk are not be involved.