Implication of Ca²⁺ stores on ciguatoxin-evoked release of catecholamines.

<p>Chromaffin cells were pre-treated (20 min) with increasing concentrations of caffeine and subsequently exposed (black bars) or not (white bars) to P-CTX-1B (10 nM), before measuring the amount of secreted catecholamines. The P-CTX-1B-induced catecholamine release is decreased following depletion of internal caffeine-sensitive Ca²⁺ stores. A representative graph for three experiments carried out in quadruplicate is shown.