【摘要】 采用皮下递增注射吗啡５ｄ后，经纳络酮催瘾建立吗啡戒断模型。观察褪黑激素（ｍｅｌａｔｏｎｉｎ，ＭＴ）对吗啡成瘾大鼠戒断后平均动脉血压（ｍＡＢＰ）和心率（ＨＲ）的影响。结果表明，ＭＴ有明显抑制吗啡成瘾大鼠戒断后的高血压症和心加速症的作用，并呈剂量效应关系。ｉｍα受体阻断剂ｒｅｇｉｔｉｎｅ能完全阻断吗啡戒断后ｍＡＢＰ的升高。此外，吗啡成瘾大鼠血清中去甲肾上腺素的含量较正常大鼠高，ＭＴ可使之降至正常水平。因此，我们认为吗啡戒断时出现的高血压症与心动过速症与交感神经系统活动亢进有关，ＭＴ对吗啡戒断时心血管反应的抑制可能是通过抑制交感系统而实现。更多还原

【Abstract】 The model of morphine dependent rats was established by gradually increasing the doses of morphine by subcutaneous injection(from 5 mg·kg -1 to 50 mg·kg -1 , 5 days). The effects of melatonin(MT) on the mean arterial blood pressure(mABP) and heart rate(HR) were studied in naloxone precipitated rats. MT was found to inhibit the hypertention and tachycardiac syndromes in morphine withdrawal rats in dose dependent manner. The concentration of serum norepinephrine(NE) was shown to be decreased by MT. Moreover, regitine was shown to inhibit the increase of mABP in morphine withdrawal rats, but can not inhibit the increase of HR. These results suggest that the inhibitory effect of MT on hypertension and tachycardiac syndromes in morphine withdrawal rats may be mediated by the inhibitory effect of the drug on the sympathetic system.更多还原