Gillo B, Lass Y
Br J Pharmacol. 1984 Aug;82(4):783-9. doi: 10.1111/j.1476-5381.1984.tb16474.x.
The effects of the steroid anaesthetic alphaxalone on acetylcholine (ACh)-induced ionic channels were studied in voltage clamped 'myoballs' in culture. Alphaxalone produced a reversible blockade of the ACh-evoked inward current, ED50 = 6.0 microM. The ACh reversal potential (-5.0 mV), the single channel conductance (13.5 pS) and mean open time (3.6 ms) were unchanged by the drug. Thus, alphaxalone produced an 'all or none' block of the ionic channel. In double pulse conditioning experiments, alphaxalone produced an additional inhibition with a time constant of recovery (550 ms) much longer than the time constant of recovery of the normal desensitization (250 ms). It was concluded that alphaxalone blocks active (open) ionic channels.
在培养的电压钳制“肌球”中研究了类固醇麻醉剂α-羟孕酮对乙酰胆碱(ACh)诱导的离子通道的影响。α-羟孕酮对ACh诱发的内向电流产生可逆性阻断,半数有效剂量(ED50)=6.0微摩尔。药物对ACh反转电位(-5.0毫伏)、单通道电导(13.5皮安)和平均开放时间(3.6毫秒)均无影响。因此,α-羟孕酮对离子通道产生“全或无”阻断。在双脉冲条件实验中,α-羟孕酮产生额外抑制作用,其恢复时间常数(550毫秒)远长于正常脱敏的恢复时间常数(250毫秒)。得出的结论是,α-羟孕酮阻断活性(开放)离子通道。