FIGURE 3.

Effect of tetracaine on CRC of permeabilized Drosophila S₂R⁺ cells. Experimental conditions were as described in the legend to Fig. 2, except that the concentration of P_i was 1 mm. A, extramitochondrial Ca²⁺ was monitored, and CRC was determined by stepwise addition of 10 μm Ca²⁺ pulses (arrows) in the absence of further additions (trace a) or in the presence of 0.5 or 1 mm tetracaine (traces b and c, respectively). B, The amount of Ca²⁺ accumulated prior to onset of Ca²⁺-induced Ca²⁺ release in presence of the stated concentrations of tetracaine was normalized to that obtained in absence of tetracaine (CRC₀).