Figure 2.

The whole-cell patch clamp technique shows examples of two types of Ca²⁺ currents in a human ventricular single cell. (A) Voltage-dependence of the low threshold of I_Ca (open circles) and separation of the high-threshold I_Ca (open triangles). (B) Peak current trace of the low-threshold I_Ca recorded from a holding potential (HP) of −80 mV with a voltage step (VS) to −10 mV. (C) Current trace of the high-threshold I_Ca was recorded from an HP of −50 mV with a VS to +20 mV. (D) Steady-state inactivation relationship of the low- (open circles) and high-threshold (open triangles) I_Ca. (E) Low-threshold current recorded from HP of −65 mV with a VS to −20 mV. (F) High-threshold current trace recorded from HP of −17 mV with a VS to +20 mV. Currents were measured at the peak (modified from [44]).