Biochimica Et Biophysica Acta
Ca2+ activation and membrane electroporation by 10-ns and 4-ms electric pulses (nsEP and msEP) were compared in rat embryonic cardiomyocytes. The lowest electric field which triggered Ca2+ transients was expectedly higher for nsEP (36 kV/cm)than forms EP (0.09 kV/cm) but the respective doses were similar (190 and460 mJ/g). At higher intensities, both stimuli triggered prolonged firing in quiescent cells. An increase of basal Ca2+ level by N10 nM in cells with blocked voltage-gated Ca2+ channels and depleted Ca2+ depot occurred at 63 kV/cm (nsEP) or 0.14 kV/cm (msEP) and was regarded as electroporation threshold. These electric field values were at 150–230% of stimulation thresholds for both msEP and nsEP, notwithstanding a 400,000-fold difference in pulse duration. For comparable levels of electroporative Ca2+ uptake, msEP caused at least 10-fold greater uptake of propidium than nsEP, suggesting increased yield of larger pores. Electroporation by msEP started Ca2+ entry abruptly and locally at the electrode-facing poles of cell, followed by a slow diffusion to the center. In a stark contrast, nsEP evoked a “supra-electroporation” pattern of slower but spatially uniform Ca2+ entry. Thus nsEP and msEP had comparable dose efficiency, but differed profoundly in the size and localization of electropores.
Original Publication Citation
Semenov, I., Zemlin, C., Pakhomova, O. N., Xiao, S., & Pakhomov, A. G. (2015). Diffuse, non-polar electropermeabilization and reduced propidium uptake distinguish the effect of nanosecond electric pulses. Biochimica Et Biophysica Acta, 1848(10), 2118-2125. doi:10.1016/j.bbamem.2015.06.018
Semenov, Iurii; Zemlin, Christian; Pakhomova, Olga N.; Xiao, Shu; and Pakhomov, Andrei G., "Diffuse, Non-Polar Electropermeabilization and Reduced Propidium Uptake Distinguish the Effect of Nanosecond Electric Pulses" (2015). Bioelectrics Publications. 202.
0000-0002-0302-1355 (Semenov), 0000-0003-4950-4130 (Pakhomova), 0000-0002-0375-8373 (Xiao)