期刊名称:Proceedings of the National Academy of Sciences
印刷版ISSN:0027-8424
电子版ISSN:1091-6490
出版年度:1982
卷号:79
期号:6
页码:2082-2085
DOI:10.1073/pnas.79.6.2082
语种:English
出版社:The National Academy of Sciences of the United States of America
摘要:We have studied the effects of batrachotoxin (BTX) on sodium channels in hybrid mouse neuroblastoma cells NG108-15 by using the suction pipet voltage clamp method. BTX-modified sodium channels activate with first-order kinetics and, over most of the potential range, activate more slowly than normal sodium channels. The peak conductance-voltage curve and the time constant of activation-versus-voltage curve for BTX-modified sodium channels are shifted about 50 mV in the hyperpolarizing direction compared to the corresponding curves for normal sodium channels. There is no change in the slope of the conductance-voltage curve. These results suggest that BTX slows down one of the steps leading to channel opening, which consequently becomes rate-limiting. In addition, BTX eliminates both fast and slow inactivation.