Mepivacaine reduces calcium transients in isolated murine ventricular cardiomyocytes

Fig. 1. Representative Ca2+ transients’ traces to the dose-response effect of mepivacaine at 0, 10, 20, 40, 50, 75 and 100 μM (a). Log dose-response analysis of the peak area (nM*s) parameter was analyzed, obtaining the IC50 value of 50.85 ± 6.79 μM

Fig. 2. Representative Ca2+ transients trace demonstrating the inhibitory effect of mepivacaine at half maximal inhibitory concentration (IC50) on in isolated mouse ventricular cardiomyocytes (a). Summarized data for the effect of mepivacaine (IC50) on biophysical parameters describing the general aspects of the Ca2+ transients: baseline (b) peak area (c), Duration at 50% of the maximum D50 (d) and duration (e). Results are expressed as mean ± SEM. Symbol (*) indicates significant change from control (p < 0.05). n = 42 cells for control and n = 29 cells for mepivacaine group

Fig. 3. Summarized data for the effect of mepivacaine at IC50 on Ca2+ release’s biophysical parameters obtained from Ca2+ transients: peak (a), slope (b) and time to peak (c). Results are expressed as mean ± SEM. Symbol (*) indicates significant change from control (p < 0.05). n = 42 cells for control and n = 29 cells for mepivacaine group

Fig. 4. Representative Ca2+ transient traces from isolated murine cardiomyocyte under the effect of NCX blockers and in combination with mepivacaine. (a) Response of Ca2+ transient under 1 mM NiCl2 (green) did not significantly altered both baseline (solid black line) neither peak area parameters. Gray arrows indicate electrical stimulation. The combination of 50 μM mepivacaine with 1 mM NiCl2 (brown) induced arrhythmic activity and significant increase in the baseline (p < 0.01; dashed black line). n = 27 cells for control, 31 cells for NiCl2 1 mM and 10 cells for Mepivacaine 50 μM + NiCl2 1 mM. (b) Response of Ca2+ transient under 10 μM ORM-10103 (blue) did not significantly altered both baseline (solid black line) neither peak area parameters. The combination of 50 μM mepivacaine with 10 μM ORM-10103 (purple) induced arrhythmic activity and significant increase in the baseline (p < 0.05; dashed black line). n = 27 cells for control, 24 cells for ORM-10103 10 μM and 10 cells for mepivacaine 50 μM + ORM-10103 10 μM