Effect of calmodulin antagonists on survival and on [Ca²⁺]_i. A, Percentages of MTN survival after 24 hr in NE cultures (open bars), MEX-treated cultures (black bars), and high potassium-treated cultures (cross-hatched bars). Groups of bars represent survival in cultures without drugs (ND) or cultures treated with 5 μg/ml W12 or W13. Values are the mean ± SEM. Asterisks indicate values significantly different (p < 0.05) from control, MEX-treated cultures. B, Intracellular calcium level in untreated cultures (BASAL) and in cultures treated with high potassium alone (30K) or high potassium supplemented with 5 μg/ml W12 (W12) or 5 μg/ml W13 (W13). [Ca²⁺]_i was measured after 5 min (open bars) and 24 hr (black bars) of treatment. [Ca²⁺]_i is plotted as the mean ± SEM.