Effects of N-ethylmaleimide treatment on the action potential Na+-ionophore of cultured neuroblastoma cells.
Treatment of murine neuroblastoma N18 cells with N-ethylmaleimide under conditions that favor diminution of membrane potential leads to a 65% increase in the rate of veratridine-stimulated, tetrodotoxin-sensitive Na+ uptake and to a 50% decrease in the concentration of veratridine required for half-maximal stimulation. This modification does not appear to occur in N18 cells having a normal membrane potential of approx. -40 mV. The data are consistent with the involvement of a sulfhydryl group in the Na+ channel inactivation gate and in the conformational change in this gate which results in closing of the channel.
D000200:Action Potentials / Q000187:drug effects; D000818:Animals; D002478:Cells, Cultured; D005033:Ethylmaleimide / Q000494:pharmacology*; D007473:Ion Channels / Q000187:drug effects*; D007476:Ionophores / Q000378:metabolism; D051379:Mice; D009374:Neoplasms, Experimental / Q000378:metabolism; D009447:Neuroblastoma / Q000378:metabolism*; D011188:Potassium / Q000502:physiology; D012964:Sodium / Q000378:metabolism*; D013779:Tetrodotoxin / Q000494:pharmacology; D014701:Veratridine / Q000494:pharmacology
D007473:Ion Channels; D007476:Ionophores; D013779:Tetrodotoxin; D014701:Veratridine; D012964:Sodium; D005033:Ethylmaleimide; D011188:Potassium