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，此效应是通过中枢神经系统内的阿片受体介导的 OBJECTIVE: To observe the effect of intrathoracic injection of MetEnk on splenic sympathetic nerve activity. Methods: Thirty male Sprague-Dawley rats were divided into five groups with 6 rats in each group. Physiological saline (10 μg, 100 μg) was injected into the third ventricle. The splenic sympathetic nerve impulse Changes in discharge activity. Results: The third ventricle injection of Met  En after a dose-dependent increase in splenic sympathetic nerve impulse discharge activity. Prior effects of the opioid receptor blocker naloxone (Nal) blocked this effect, but Nalpha alone had no effect on splenic sympathetic excitability. In the experiment, the effect of MetEnk on blood pressure and body temperature was also observed. It was found that blood pressure increased with the increase of splenic sympathetic nerve impulses, but the body temperature did not change significantly. Conclusion: The third intracerebroventricular injection of MetEnk can significantly enhance the impulse discharge activity of splenic sympathetic nerve, which is mediated through opioid receptors in the central nervous system