Effects of Picosecond Pulsed Electric Fields on U937 and C6 Cells

Experiments have been conducted to investigate the cell response to the picosecond pulsed electric fields (psPEF) with pulse repetition frequency (PRF) of 1kHz. Exposure of U937 cells and C6 cells to psPEF with PRF of 1kHz resulted in the decreased cell viability in both cell lines but the C6 cells were more sensitive than U937 cells. Moreover, the treatment of psPEF also significantly increased the intracellular fluorescence intensity in U937 cells which pre-incubated with Fluo-4, a common Ca2+ indicator. It demonstrated that the psPEF exposure led to the enhancement of intracellular Ca2+ level. While the application of Manidipine, a calcium channel inhibitor didn't block the Ca2+ induced activation of calmodulin kinase (CaMK), which indicated that the calcium channel inhibited by Manidipine did not play a role in the psPEF exposure induced elevation of intracellular Ca2+ level.