脑室内注射甲硫-脑啡肽对脾交感神经活动的影响

Intracerebroventricular injection of metenkephalin stimulates splenic sympathetic nerve activity

目的：观察第三脑室注射甲硫脑啡肽（ＭｅｔＥｎｋ）对脾交感神经放电活动的影响．方法：３０只雄性ＳｐｒａｇｕｅＤａｗｌｅｙ大鼠分为５组，每组６只，分别于第三脑室内微量注射生理盐水，ＭｅｔＥｎｋ（１０μｇ，１００μｇ），用电生理学的方法观察脾交感神经冲动放电活动的变化．结果：第三脑室注射ＭｅｔＥｎｋ后，可剂量依赖性地增强脾交感神经冲动放电活动．事先ｉｖ阿片受体阻断剂纳络酮（Ｎａｌ）可以阻断这种效应，但单独使用Ｎａｌ对脾交感神经兴奋性没有影响．在实验中同时观察了ＭｅｔＥｎｋ对血压和体温的影响，发现随脾交感神经冲动数的增多开始后，血压亦有升高，但体温无明显变化．结论：第三脑室内注射ＭｅｔＥｎｋ能显著地增强脾交感神经冲动放电活动。

Aim: To investigate the action of Metenkephalin(MetEnk) injected into the third cerebral ventricle on the splenic sympathetic nerve activity Methods:Thirty male SpragueDawley rats were divided into 5 groups,6 rats in each group. After microinjection of saline,MetEnk(10 μg,100 μg) respectively into the third cerebral ventricle, the splenic sympathetic nerve activity was observed with electrophysidogical method Results: Injection of MetEnk into the third cerebral ventricle produced a increase of splenic sympathetic nerve filaments  This effect could be blocked by the intravenous injection of opioid receptor antagonist naloxone(Nal), while only intravenous injection of Nal had no effect on the splenic nerve activity We also observed the effects of MetEnk on the blood pressure and body temperature during the experiment and found that the blood pressure increased with the enhancement of discharge of splenic nerve activity, while no changes of body temperature were observed Conclusion: The injection of MetEnk into the third cerebral ventricle stimulates the splenic sympathetic nerve activity effectively, which is mediated by opioid receptors in the central nervous system