Changes in Ca2+ release in human red blood cells under pulsed magnetic field

Abstract

Since Ca2+ is related to a highly versatile intracellular signal to regulate many different cellular processes, the role of Ca2+ and its concentration in red blood cells (RBCs) are very important. Accordingly, in this study, we have elucidated the relationship between pulsed magnetic field (PMF) and intracellular Ca2+ level to understand how PMF affects oxidative stressed RBCs. In addition, the effect of verapamil on RBCs in Ca2+ level, compared to the effect of PMF was investigated because verapamil, as a reducing agent, blocks Ca2+ influx into RBCs. Tert-butyl hydroperoxide (tBHP) was used to induce oxidative stress in RBCs with various concentrations of 0.1 to 400 mM. Our PMF stimulator has the maximum intensity of 0.27 T at a transition time of 102 μs with pulse intervals of 1 Hz. Our result showed that Ca2+ level is remarkably decreased in RBCs treated verapamil, RBCs exposed to PMF after tBHP(0.1 mM) treatment, and RBCs treated tBHP(0.1 mM) after PMF exposure, respectively. This means that PMF not only reduces Ca2+ level of inner RBC effectively but also blocks inhibiting Ca2+ pump ATPase activity. Also it seems that PMF appears to act similar to reducing agent. For hemolysis change in oxidative stressed RBCs with or without PMF, using western blot and gel analysis, it is observed that hemolysis declines in control RBCs and tBHP(0.1 mM)-treated RBCs exposed to PMF, and in verapamil treated sample. The RBC deformability (RBCD) was also improved after PMF exposure. Therefore, the results of the present study support that PMF gives RBCs positive effect consistently in Ca2+ level and plays a role in preventing RBC hemolysis from oxidative stress and improving RBCD. In conclusion, our study suggests a possibility to use PMF as a new modality in improving circulatory regulation in hemodynamic derangements in disease. We need to optimize PMF intensity and stimulated duration for clinical use.