Ary T E, Frank G B
Eur J Pharmacol. 1983 Oct 28;94(3-4):211-7. doi: 10.1016/0014-2999(83)90410-7.
Intracellular microelectrode studies were conducted to examine the actions of the optical isomers levorphanol and dextrorphan on the isolated frog sartorius muscle preparation. Both isomers, in bath concentrations which had minimal effect on action potential amplitude and gNa (3 X 10(-5) M), caused a large depression of gK. High bath concentrations (3 X 10(-4) M) of both drugs caused an initial depression of sodium and potassium conductance processes, gNa and gK, respectively, however only levorphanol, but not dextrorphan, could produce a specific, late-occurring depression of gNa that could be blocked by the opiate antagonists, nalorphine or naloxone. These findings indicate that the late-occurring depressant effect on gNa is stereospecific and reinforce previous findings which demonstrated that opiate drugs interact with opiate receptors associated with the sodium channels of the frog muscle fibre membranes.
进行细胞内微电极研究，以检测光学异构体左啡诺和右啡烷对分离的青蛙缝匠肌标本的作用。两种异构体在浴槽浓度下对动作电位幅度和钠电导（gNa）影响极小（3×10⁻⁵M），却能引起钾电导（gK）大幅降低。两种药物的高浴槽浓度（3×10⁻⁴M）分别引起钠和钾电导过程gNa和gK的初始降低，然而只有左啡诺，而非右啡烷，能产生一种特定的、迟发性的gNa降低，该降低可被阿片拮抗剂烯丙吗啡或纳洛酮阻断。这些发现表明，对gNa的迟发性抑制作用具有立体特异性，并强化了先前的研究结果，即阿片类药物与青蛙肌肉纤维膜钠通道相关的阿片受体相互作用。
