Abstract
Human vascular endothelial cells (HUVEC) were exposed to air electric fields of 30 kV/m, 50 Hz for 24 hr. After exposure, the change in intracellular Ca2+ concentration ([Ca2+]i) induced by the vasoactive substances ATP and histamine were determined using confocal laser scanning microscopy. A statistically significant increase in [Ca2+]i was observed following stimulation with 100 μM ATP, compared with the results in sham-exposed cells (22%, p<0.05, n=20). No changes in [Ca2+]i due to the field were observed after stimulation with histamine, showing that the effect of the field on the change in [Ca2+]i was agonist-specific. The Ca2+ concentration in the medium was low, suggesting that the ATP-induced increase in [Ca2+]i in cells exposed to electric fields was due to the release of Ca2+ from intracellular stores. The results suggested that the applied low-frequency electric field affected the function of HUVEC via a change in [Ca2+]i.