Frank G B, Marwaha J
Can J Physiol Pharmacol. 1978 Jun;56(3):501-8. doi: 10.1139/y78-075.
Extracellular and intracellular microelectrode studies were conducted to test the actions and interactions of opiate agonists, antagonists, and procaine on action potentials in frog sartorius muscles. Extracellular studies showed that morphine, methadone, propoxyphene, and procaine all depressed action potential production. Low concentrations of naloxone or naltrexone antagonized the excitability depression produced by the three opiate agonists but not the depression produced by procaine. Intracellular studies revealed that certain concentrations of the opiate agonists produced a biphasic decline in the stimulus-induced increase in sodium conductance (gNa). Naloxone or naltrexone antagonized only the second phase of this decline. These results show that part of the excitability depression produced by opiate agonists is due to an action on opiate drug receptors.
进行了细胞外和细胞内微电极研究，以测试阿片类激动剂、拮抗剂和普鲁卡因对青蛙缝匠肌动作电位的作用及相互作用。细胞外研究表明，吗啡、美沙酮、丙氧芬和普鲁卡因均抑制动作电位的产生。低浓度的纳洛酮或纳曲酮可拮抗三种阿片类激动剂引起的兴奋性降低，但不能拮抗普鲁卡因引起的降低。细胞内研究显示，特定浓度的阿片类激动剂可使刺激诱导的钠电导（gNa）增加呈双相下降。纳洛酮或纳曲酮仅拮抗这种下降的第二阶段。这些结果表明，阿片类激动剂引起的部分兴奋性降低是由于对阿片类药物受体的作用。
