Neuromuscular block produced by polymyxin B: interaction with end-plate channels.
The effect of polymyxin B on the amplitude and kinetics of miniature end-plate currents and acetylcholine-induced current fluctuations was studied in voltage-clamped fibers of the snake. Polymyxin B produced a voltage and concentration dependent reduction in both mean peak MEPC amplitude and the time constant of MEPC decay. A concomitant decrease in mean channel lifetime and single channel conductance indicated that a major mechanism for the neuromuscular block produced by polymyxin B is endplate channel blockade.
D000818:Animals; D066298:In Vitro Techniques; D007473:Ion Channels / Q000187:drug effects*; D008564:Membrane Potentials / Q000187:drug effects; D009045:Motor Endplate / Q000187:drug effects*; D009466:Neuromuscular Blocking Agents; D009469:Neuromuscular Junction / Q000187:drug effects*; D011112:Polymyxin B / Q000494:pharmacology*; D011113:Polymyxins / Q000494:pharmacology*; D012911:Snakes
D007473:Ion Channels; D009466:Neuromuscular Blocking Agents; D011113:Polymyxins; D011112:Polymyxin B