Baum V C
Department of Anesthesiology, University of California, Los Angeles.
Anesth Analg. 1993 Jan;76(1):18-23. doi: 10.1213/00000539-199301000-00004.
The mechanism(s) of action of anesthetics on cell membrane ionic currents are not known. To investigate this further the effects of clinically relevant concentrations of ketamine, methohexital, and propofol on the delayed rectifier (IK) and the inward rectifier (IK1) currents of single dispersed guinea pig ventricular myocytes were studied. These voltage-gated currents are major components of cardiac cell electrophysiologic function regulating resting potential and repolarization. Each of the three anesthetics had a distinct spectrum of activity. Ketamine (10(-4) M) decreased IK1 (P < 0.05) but had no effect on IK. Methohexital (10(-4) M) had no significant effect on either current. Propofol (2.8 x 10(-5) M) resulted in significant depression of IK (P < 0.001) but had no effect on IK1. These results suggest that these intravenous anesthetics may have more specific effects on sarcolemma than volatile anesthetics, whose effects may be more generalized membrane effects.
麻醉剂对细胞膜离子电流的作用机制尚不清楚。为进一步研究这一问题，我们研究了临床相关浓度的氯胺酮、美索比妥和丙泊酚对单个分散的豚鼠心室肌细胞延迟整流钾电流（IK）和内向整流钾电流（IK1）的影响。这些电压门控电流是调节静息电位和复极化的心脏细胞电生理功能的主要组成部分。三种麻醉剂中的每一种都有独特的活性谱。氯胺酮（10^(-4) M）使IK1降低（P < 0.05），但对IK无影响。美索比妥（10^(-4) M）对两种电流均无显著影响。丙泊酚（2.8×10^(-5) M）导致IK显著降低（P < 0.001），但对IK1无影响。这些结果表明，这些静脉麻醉剂对肌膜的作用可能比挥发性麻醉剂更具特异性，挥发性麻醉剂的作用可能是更普遍的膜效应。
