de Hemptinne A
Eur J Cardiol. 1978 Jun;7 Suppl:5-15.
Voltage clamp experiments were performed to analyse the voltage and time dependence of the secondary inward current in frog atrial preparations. The fibers were treated with tetrodotoxin and tetraethylammonium or cesium to suppress the fast inward current and reduce the outward current; Cl- was replaced by CH3SO-4 to reduce the background current. Evidence is obtained suggesting that the inactivation process of the calcium dependent inward current is relatively rapid in the frog atrium. The current-voltage relationship of this current system appears to be nonlinear. The calcium dependent inward current transient is followed by a subsidiary net inward current which is presumably mainly Na+ dependent and underlies the depolarization tail of the action potential.
进行电压钳实验以分析蛙心房标本中次级内向电流的电压和时间依赖性。用河豚毒素、四乙铵或铯处理纤维，以抑制快速内向电流并减少外向电流；用CH3SO-4取代Cl-以减少背景电流。有证据表明，蛙心房中钙依赖性内向电流的失活过程相对较快。该电流系统的电流-电压关系似乎是非线性的。钙依赖性内向电流瞬变之后是一个辅助性净内向电流，其可能主要依赖于Na+，并构成动作电位去极化尾的基础。
