The effects of extracellular Ca²⁺ on ASIC currents in freshly isolated anterior pituitary cells.

<p><b>A</b>. Representative ASIC currents elicited by pH 5.5 with various concentrations of extracellular Ca²⁺. Holding potential was −70 mV. Ca²⁺ concentrations from 0 µM to 10 mM at pH 7.4 were applied for 2 minutes and ASIC currents were activated by pH 5.5 for 5 sec with the same Ca²⁺ concentration. <b>B</b>. Summary data showing the dose-dependent block of ASIC currents by Ca²⁺. The IC₅₀ of Ca²⁺ block was 357±20 µM (n = 7).