Mepivacaine reduces calcium transients in isolated murine ventricular cardiomyocytes

Abstract

Background: The potential mechanism of mepivacaine's myocardial depressant effect observed in papillary muscle has not yet been investigated at cellular level. Therefore, we evaluated mepivacaine's effects on Ca 2+ transient in isolated adult mouse cardiomyocytes. Methods: Single ventricular myocytes were enzymatically isolated from wild-type C57Bl/6 mice and loaded with 10 μM fluorescent Ca 2+ indicator Fluo-4-AM to record intracellular Ca 2+ transients upon electrical stimulation. The mepivacaine effects at half-maximal inhibitory concentration (IC 50) was determined on calibrated cardiomyocytes' Ca 2+ transients by non-parametric statistical analyses on biophysical parameters. Combination of mepivacaine with NCX blockers ORM-10103 or NiCl 2 were used to test a possible mechanism to explain mepivacaine-induced Ca 2+ transients' reduction. Results: A significant inhibition at mepivacaine's IC 50 (50 μM) on Ca 2+ transients was measured in biophysical parameters such as peak (control: 528.6 ± 73.61 nM vs mepivacaine: 130.9 ± 15.63 nM; p < 0.05), peak area (control: 401.7 ± 63.09 nM*s vs mepivacaine: 72.14 ± 10.46 nM*s; p < 0.05), slope (control: 7699 ± 1110 nM/s vs mepivacaine: 1686 ± 226.6 nM/s; p < 0.05), time to peak (control: 107.9 ± 8.967 ms vs mepivacaine: 83.61 ± 7.650 ms; p < 0.05) and D 50 (control: 457.1 ± 47.16 ms vs mepivacaine: 284.5 ± 22.71 ms; p < 0.05). Combination of mepivacaine with NCX blockers ORM-10103 or NiCl 2 showed a significant increase in the baseline of [Ca 2+ ] and arrhythmic activity upon electrical stimulation. Conclusion: At cellular level, mepivacaine blocks Na + channels, enhancing the reverse mode activity of NCX, leading to a significant reduction of Ca 2+ transients. These results suggest a new mechanism for the mepivacainereduction contractility effect.

Molecular profiling of individual FDA-approved clinical drugs identifies modulators of nonsense-mediated mRNA decay

“…52 , 53 , 54 , 55 Tocainide, procaine hydrochloride, and mepivacaine hydrochloride are voltage-gated sodium channel modulators. 56 , 57 , 58 Vindesine sulfate, podofilox, albendazole, and vinorelbine tartrate are microtubule modulators. 59 , 60 , 61 We also listed the top 15 ranked drugs that decreased the N_Ptbp2 / F_Ptbp2 , N_Hnrnpl / F_Hnrnpl , and N_Tra2b / F_Tra2b ratio ( Figures 4 D–4F).…”

Cardiomyocyte depolarization triggers NOS-dependent NO transient after calcium release, reducing the subsequent calcium transient

“…Single cardiomyocyte isolation using Langendorff perfusion set-up was previously described [ 56 , 67 , 111 ] with few modifications (Supplemental Information Material & Method). The isolated heart was cannulated in between the atria for the Perfusion Solution (in mM: 135 NaCl, 4 KCl, 1 MgCl 2 , 10 HEPES, 0.33 NaH 2 PO 4 , 10 Glucose, 20 2,3-butanedione monoxime BDM, 5 Taurine, pH 7.2) connected to the 37 °C pre-warmed Langendorff set-up.…”

“…Cardiomyocytes obtained as described above from different set of five mice per treatment were used to record consecutive Ca 2+ transients in a different set-up, as previously described [ 67 , 111 ]. Isolated cardiomyocytes were incubated during 30 min with 5 µM Fluo-4-AM (Life Technologies, Carlsbad, CA, USA).…”

“…Fluo-4 AM calibration procedure for converting the voltage signal into Ca 2+ concentration was performed at the end of every experiment as previously described [ 67 , 86 , 108 , 111 ]. Briefly, the background of the petri dish was recorded in 10 different spots (no cells).…”

Traqueotomía híbrida. Una alternativa válida para pacientes críticos obesos COVID-19

“…Las características especiales de los pacientes COVID-19 transforman un procedimiento estándar como es la traqueotomía, en una situación crítica que puede producir una descompensación aguda y una rápida desaturación del paciente con el simple acto de movilizarlos. Es por ello que quizás lo ideal sería la realización de la traqueotomía en la propia habitación en la unidad de cuidados intensivos (UCI), y ahí es donde la realización de una traqueotomía percutánea presenta grandes ventajas 1 , 2 .…”