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：1983
卷号：80
期号：6
页码：1743-1745
DOI：10.1073/pnas.80.6.1743
语种：English
出版社：The National Academy of Sciences of the United States of America
摘要：A voltage-dependent inward calcium current insensitive to tetrodotoxin has been measured in internally perfused or dialyzed squid giant axons. Sodium conductance was blocked by tetrodotoxin, and potassium conductance was irreversibly destroyed by the lack of potassium in the external and internal medium. Chloride conductance was eliminated by replacement of chloride with methylsulfonate. The calcium current was activated at about -40 mV and it peaked at about 0 mV. The peak inward current was 3 microA/cm2 when external Ca was 80 mM and 0.9 microA/cm2 in 8 mM Ca. In 80 mM Ca, the calcium current is turned on in less than 10 msec, and it does not decay appreciably for pulses up to 70 msec in duration. Barium can replace calcium, and cadmium blocks the calcium current.
