Kinetic analyses of electrically evoked Ca²⁺ transients in intact FDB fibers after acute exposure to BTP2. (A–C) Representative mag-fluo-4 traces with the decay phase shown on an expanded time scale and fitted with a double exponential equation (green lines) from FDB fibers before exposure to DMSO (A), 10 µM BTP2 (B), or 20 µM BTP2 (C). Insets: Fitted parameters for each condition, including the fast and slow amplitudes of decay (A_fast and A_slow), fast and slow time constants of decay (τ_fast and τ_slow), and goodness of fit values (R²). (D) Average (± SEM) maximal mag-fluo-4 transient rate of rise (Max dF/dt) before (0 min) and after (2 min) exposure to DMSO control (black), 10 µM BTP2 (blue), or 20 µM BTP2 (red). (E) Averaged (± SEM) peak amplitudes of the fast (A_fast, solid bars) and slow (A_slow, checked bars) components of the decay phase of the mag-fluo-4 transient before and 2 min after exposure to DMSO control (black), 10 µM BTP2 (blue), or 20 µM BTP2 (red). (F and G) Average (± SEM) fast (τ_fast; F) and slow (τ_slow; G) time constants of the decay phase of the mag-fluo-4 transient before and 2 min after exposure to DMSO control (black), 10 µM BTP2 (blue), or 20 µM BTP2 (red). n = 12–36 cells from three to five mice for each group; two-way ANOVA with Tukey post hoc test. P = 0.37–0.99 for pairwise post hoc comparisons in D; P = 0.41–0.99 for pairwise comparisons in E; P = 0.08–0.99 for pairwise comparisons in F; P = 0.67–0.99 for post hoc comparisons in G.