TNP increases while Gd3+ decreases BASIC activity in a dose-dependent manner.

A) Representative current traces showing the concentration-dependent activation of BASIC by TNP. Upper panel, increasing concentrations of TNP were applied to a rBASIC expressing oocyte. Lower panel, increasing concentrations of TNP were co-applied with 2 mM UDCA. Dotted lines represent the 0 current level. B) Concentration-response curves for TNP in the absence (open circles) and presence (closed circles) of 2 mM UDCA. Currents were normalized to the maximum currents in the presence of TNP, which had amplitudes of 3.9±0.4 µA and 12.1±2.5 µA (n = 10) in the absence and presence of 2 mM UDCA, respectively. The current amplitude of 2 mM UDCA alone was 4.1±0.4 µA (n = 10). Error bars represent SEM, curves were fitted to the Hill equation. C) Representative current trace of a non-injected oocyte treated with increasing concentrations of TNP. D) Representative current traces showing the concentration-dependent inhibition of BASIC by Gd3+. Upper panel, increasing concentrations of Gd3+ were applied to a rBASIC expressing oocyte. Lower panel, increasing concentrations of Gd3+ were co-applied with 2 mM UDCA. Dotted lines represent the 0 current level. E) Concentration-response curves for Gd3+ in the absence (closed circles) and presence (open circles) of 2 mM UDCA. Currents were normalized to the maximum currents in the absence of Gd3+, which had amplitudes of 1.2±0.2 µA and 3.2±0.6 µA (n = 10) in the absence and presence of 2 mM UDCA, respectively. Error bars represent SEM, curves were fitted to the Hill equation. F) Representative current trace of a non-injected oocyte treated with increasing concentrations of Gd3+.