κ-阿片受体的负性肌力作用及其对β-肾上腺素受体的调节

摘要

AIM　To investigate the negative inotropic effects of U50, 488H (a selective κ-opioid receptor agonist) on heart and its modulat ory effects to β-adr enoceptor (β-AR). METHODS　①The effects of U50, 488H on t he heart rate (HR), arterial blood pressure (ABP), left ventricular pressure (LVP) and ±dp/dtmax wer e observed in rabbits; ② The isolated rats hearts were perfused and the HR, LVP and ±dp/dtmax were measured. RESULTS　①U50, 488H can depress th e HR, LVP and ±dp/ dtmax in rabbits hearts; ②U50, 488H can reduce the HR, LVP and ±dp/dtmax in isolated rats hearts; ③The positive effects of isoproterenol (a selective β-adrenoceptor ag onist) were weaken in presence of U50, 488H; CONCLUSION　①U50, 488H ca n depress the basal cardiac activity; ②U50, 488H can reduce the activity of isoproterenol -stimulated heart, suggesting that κ-opioid receptor had the negative modulato ry effects to β-AR on heart%目的研究U50, 488H（选择性κ-阿片受体激动剂）对心脏的负性肌力作用特点及对β-肾上腺素受体（β-AR）的调节作用. 方法①整体动物实验，观察U50, 488H对家兔心率（HR）、动脉压（ABP）、左心室内压（LVP）及其微分（±dp/dtmax）的影响；②利用Langerdoff装置离体灌流大鼠心脏，观察U50, 488H对HR，LVP和±dp/dtmax及β- AR正性肌力作用的影响. 结果①U50, 488H可显著降低家兔的HR，ABP，LVP及±dp/d tmax；②U50, 488H对离体大鼠心脏的HR, ABP, LVP及±dp/dtmax有降低作用；③在U50, 488H 存在的情况下，激动β-AR所引起的LVP的升高可被显著抑制. 结论①U50, 488 H对心脏具有负性肌力作用；②U50,488H可抑制β-AR的正性肌力作用，提示κ-阿片受体对β- AR具有负性调节作用.