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：8
页码：2240-2242
DOI：10.1073/pnas.80.8.2240
语种：English
出版社：The National Academy of Sciences of the United States of America
摘要：Electrical properties of the cell membrane were studied in the neoplastic lymphocyte, mouse myeloma cell line S194, by using the whole-cell patch clamp technique. Inward Ca2+ currents due to voltage-gated Ca2+ channels were found. The current, which decayed exponentially after reaching a peak, was first activated at about -50 mV and attained its maximum peak amplitude at about -20 mV in a 10 mM Ca2+ solution. Outward current was negligible for the potential range more negative than +30 mV. The channel was permeable to Sr2+ and Ba2+ in addition to Ca2+. Among these species, Sr2+ carried the greatest current. The time constants of the decay of the current depended neither on the species nor on the concentration of charge carrier. The steady-state inactivation was observed at potentials more negative than those at which the inward Ca2+ current was activated. Thus, we concluded that the inactivation of the channel was mainly voltage dependent. For reasons that are not yet understood, the amplitude of the Ca2+ current varied greatly among cells.
