Figure 12. Stimulation of I_Cl,Ca by extracellular Ca²⁺.

Standard intracellular solution contained 5 mm EGTA and no added Ca²⁺. Voltage clamp protocol is shown above panel A. A, when the bath solution contained 1.8 mm Ca²⁺, only a small time-dependent outward current was observed. Deactivating tail currents at −100 mV were not seen. B, increasing bath [Ca²⁺] to 10 mm stimulated outward current and a large deactivating tail current (arrow) was observed. C, current-voltage relationships of the currents in A and B. ○, 10 mm[Ca²⁺]_o. ▪, 1.8 mm[Ca²⁺]_o.