Figure 1

Endogeneous Ca²⁺ activated Cl- channels in Xenopus laevis oocyte. (A) Currents induced by extracellular Ca²⁺ in a dose dependent manner on ionomycin treated oocyte. (B) Dose response and EC₅₀ of Ca²⁺ obtained from (A). (C~F) Currents recorded after treatment of ionomycin without thapsigargin treatment. (C, G) Fast peak and slow component during Ca²⁺ applications. (G~J) Currents recorded after treatment of ionomycin followed by thapsigargin. (D, H) Second application of Ca²⁺ induces slightly reduced fast peak amplitude compared to the first peak. (E, I) Ba²⁺ does not induce the slow component. (F, J) Ba²⁺ does not induce the fast peak. (K~O) Comparison of currents under each condition. CHE+ means that current was measured with chelerythrine added intracellular solution. TG+ indicates that thapsigargin was treated on ionomycin pretreated oocytes. (K) Fast peak amplitude. (L) Slow component amplitude. (M) Summary of the experiments shown in (D) and (H); Ratio of amplitude induced by the first and the second Ca²⁺. (N) Summary of the experiments shown in (E) and (I). (O) Summary of the experiments shown in (F) and (J). n indicates number of oocytes. Error bars indicate SEMs. * indicates statistically significant difference by two-tailed t-test. *, p < 0.05; **, p < 0.01; ***, p < 0.001