Ellestad M H, Kuan P
Am J Cardiol. 1984 Nov 1;54(8):982-4. doi: 10.1016/s0002-9149(84)80129-0.
Endorphins and endorphin receptors are believed to modulate pain perception. To investigate whether naloxone, a specific antagonist, could initiate anginal pain during exercise-induced myocardial ischemia in asymptomatic patients with angiographically defined coronary artery disease, a single-blind trial was conducted in 10 men with prior positive exercise electrocardiograms. Multistage treadmill exercise tests were performed twice within a week. On the second test, patients received naloxone, 2 mg intravenously, by a syringe infusion pump. Exercise was terminated because of fatigue in 6 patients and completion of the protocol in 4. No patient reported chest pain during exercise. Naloxone did not significantly alter exercise duration, heart rate, blood pressure and ST-segment changes compared with control testing. It is concluded that endorphins do not play a significant role in the recognition of anginal pain in patients who have asymptomatic exercise-induced ischemia.
内啡肽和内啡肽受体被认为可调节疼痛感知。为研究特异性拮抗剂纳洛酮是否会在血管造影显示有冠状动脉疾病的无症状患者运动诱发心肌缺血期间引发心绞痛，对10名既往运动心电图呈阳性的男性进行了一项单盲试验。在一周内进行了两次多级跑步机运动试验。在第二次试验中，患者通过注射器输注泵静脉注射2毫克纳洛酮。6名患者因疲劳终止运动，4名患者完成试验方案。无患者在运动期间报告胸痛。与对照试验相比，纳洛酮未显著改变运动持续时间、心率、血压和ST段变化。得出的结论是，内啡肽在无症状运动诱发缺血患者的心绞痛识别中不起重要作用。
