本研究观察了大鼠接受慢性吗啡处理过程中，心脏中κ受体结合位点的变化及其对κ激动剂ＵＳ５０４８８致心律失常作用的反应。结果表明，在慢性吗啡处理过程中，心脏κ结合位点数目逐渐增加，至ｄ１０超过对照一倍以上；同时在慢性处理ｄ８和ｄ１０，鼠心对Ｕ５０４８８Ｈ的致心律失常效应出现明显的耐受。撤药后２ｄ，鼠心κ结合位点与其对κ激动剂的效应回复至对照水平，结果提示，大鼠的μ阿片耐受可引起心脏κ受体兴奋后反应的改变。 This study looked at changes in the kappa receptor binding site in the heart during chronic morphine treatment in rats and their response to arrhythmogenic effects of the kappa agonist US50488. The results showed that in the chronic morphine treatment, the number of kappa binding sites increased gradually, reaching more than d10 more than the control; at the same time in chronic treatment d8 and d10, rat heart on U50488H induced arrhythmia obvious tolerance. At 2 days after drug withdrawal, the effect of kappa-κ binding site and its effect on kappa-agonist returned to the control level, suggesting that rat μ-opioid tolerance may alter the response of cardiac kappa receptor after excitation.