Peres A, Zippel R, Sturani E, Mostacciuolo G
Department of General Physiology and Biochemistry, University of Milan, Italy.
Pflugers Arch. 1988 May;411(5):554-7. doi: 10.1007/BF00582377.
Patch-clamp experiments in the whole-cell mode have been performed in Swiss 3T3 mouse fibroblasts. Depolarizations from negative holding potential (Vh less than -60 mV) gave rise to a rapidly activating, fully inactivating, inward current of few tenths of nA in physiological saline at 35 degrees C. The current persisted when external Na+ was replaced by impermeant TMA+ and disappeared in 0 Ca2+, 1 mM EGTA. The current was reversible blocked by Co2+ and it was slightly reduced when external Ca2+ was substituted by Ba2+. Finally its reversal potential changed with Nernstian slope with increasing external Ca2+ concentrations. It is concluded that these cells possess a voltage-dependent Ca2+ channel.
在瑞士3T3小鼠成纤维细胞中进行了全细胞模式的膜片钳实验。在35℃的生理盐水中，从负的钳制电位（Vh小于-60mV）去极化会产生一种快速激活、完全失活的内向电流，电流大小为十分之几纳安。当外部Na+被不通透的TMA+取代时，该电流持续存在，而在0 Ca2+、1 mM EGTA溶液中消失。该电流可被Co2+可逆性阻断，当外部Ca2+被Ba2+取代时，电流略有降低。最后，其反转电位随着外部Ca2+浓度的增加以能斯特斜率变化。结论是这些细胞拥有电压依赖性Ca2+通道。
