Fig. 3.
The effects of TBQ on sarcolemmal currents. (A) Specimen membrane currents in response to a 100 ms depolarising pulse from −40 to 0 mV. Panels show (left to right) control, increasing concentrations of TBQ and washout. (B) Average data (n = 17 cells from 8 animals) showing peak inward current (black). The effect on the rate constant of systolic calcium removal is superimposed for reference (grey and dashed curve). (C) ICa-LI–V plot in control (open symbols) and presence of 10 μM TBQ (filled symbols). (D) Average data shows the peak outward component of the currents represented by (A). (E) Specimen IV relationship produced by a voltage ramp protocol (−120 to 40 mV) showing the control current, the current after exposure to TBQ and the TBQ sensitive current determined by subtraction of TBQ from control (ITBQ). This record is typical of 5 experiments. *p < 0.05 vs. control.