Induction of Intracellular Calcium Oscillations in Human Skin Fibroblast Populations by Sinusoidal Extremely Low-Frequency Magnetic Fields (20 Hz, 8 mT) Is Dependent on the Differentiation State of the Single Cell

Abstract

Experiments were performed to analyze whether short-term exposure to a sinusoidal extremely low-frequency electromagnetic field (20 Hz, 8 mT) can alter the dynamics of intracellular calcium in diploid human skin fibroblasts. In heterogeneous fibroblast populations, about 30% of the cells responded with a change in the oscillation activity of intracellular calcium within 40 min. It was demonstrated at the level of the single cell that the responsiveness of fibroblast populations to extremely low-frequency electromagnetic fields depends on the specific differentiation state of the exposed cell. The data obtained clearly indicate that mitotic progenitor fibroblasts respond with an enhancement of the dynamics of calcium, whereas in postmitotic fibrocytes a reduction of the dynamics was observed when the cells were co-stimulated with suboptimal concentrations of platelet-derived growth factor. Thus data from our laboratory on terminal differentiation induced by extremely low-frequency electromagnetic fields may be correlated with changes in the dynamics of Ca2+ reported here.