Figure 1. BASIC responses to bile acid are modulated by the membrane active substances chlorpromazine, trinitrophenol and Gd³⁺.

A) Representative current traces of an oocyte expressing BASIC (black trace) and a water-injected control oocyte (grey trace). Application of 2 mM UDCA induced a typical BASIC current. Co-application of 0.5 mM CPZ strongly decreased the UDCA-dependent current while co-application of 2 mM TNP strongly increased the current amplitude. The UDCA-dependent current was completely abolished by 100 µM Gd³⁺. Dotted line represents the 0 current level. B) Quantitative comparison of current amplitudes induced by UDCA alone or together with 0.5 mM CPZ, 2 mM TNP or 100 µM Gd³⁺. Currents were normalized to the current induced by UDCA alone, which had an amplitude of 1.1±0.2 µA (n = 10). Error bars represent SEM. Statistical significances were tested using one-way ANOVA followed by Tukey's multiple comparison test versus UDCA, **p<0.01, ***p<0.001.