Slow inactivation of L-type calcium current distorts the measurement of L- and T-type calcium current in Purkinje myocytes.
Slow inactivation of L-type calcium current distorts the measurement of L- and T-type calcium current in Purkinje myocytes.
复制标题
L 型钙电流的缓慢失活会扭曲浦肯野肌细胞中 L 型和 T 型钙电流的测量。
DOI：
10.1085/jgp.102.5.859
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发表时间：
1993
期刊：
影响因子：
--
通讯作者：
Cohen,IS
中科院分区：
文献类型：
--
作者：
Datyner,NB;Cohen,IS
我们用全细胞膜片钳技术研究了犬浦肯野肌细胞L-型钙电流的慢失活。慢失活是电压依赖性的。在-50 mV时可忽略不计，但在-10 inV时可超过可用icaL的一半。这种缓慢失活有两个主要后果。首先，用于测量T型电流的标准方案可能会显著高估其对总钙电流的贡献，其次，iCaL的失活与电压曲线的位置和陡度将取决于测量方法。鉴于广泛的尝试，以确定钙电流的成分，并表征他们的生物药理学，一个重要的第一步应该是确定在每种制剂的钙电流的缓慢失活的程度。
We have examined slow inactivation of L-type calcium current in canine Purkinje myocytes with the whole cell patch clamp technique. Slow inactivation is voltage dependent. It is negligible at-50 mV but can inactivate more than half of available icaL at-10 inV. There are two major consequences of this slow inactivation. First, standard protocols for the measurement of T-type current can dramatically overestimate its contribution to total calcium current, and second, the position and steepness of the inactivation versus voltage curve for iCaL will depend on the method of measurement. Given the widespread attempts to identify calcium current components and characterize them biophysically, an important first step should be to determine the extent of slow inactivation of calcium current in each preparation.