Fig. 4.

EGTA decreases amiodarone induced Ca²⁺ burst and protects against toxicity, (a) tuminescence from aequorin-coelenterazine was monitored as described in Fig. 1a upon addition of 40 µM amiodarone (20 µL of stock; arrow). EGTA (1–6 µL) was added from a stock solution (200 mM, pH 8.8). No change in extracellular pH was observed upon EGTA addition. Note the decrease in amplitude and delay in Ca²⁺ burst with increasing EGTA (1.2, 2.3, 4.6, and 6.8 mM final concentration), (b) Viability of cultures treated in (a) was assessed on YPD agar, immediately following luminescence measurements, as described in Fig. 2a. EGTA concentrations ranged from 1.2 to 6.8 mM.