Acute Effects of Low-frequency Electromagnetic Fields on Leukocyte-endothelial Interactions In Vivo

Abstract

Background: To clarify the effect of extremely low frequency electromagnetic field (ELF-EMF) on the microcirculatory system, acute effects on leukocyteendothelium interactions resulting from ELF-EMF exposure were examined with conscious BALB/c mice by means of a dorsal skinfold chamber. Materials and Methods: The fluorescent dye, rhodamine 6G, was injected into the caudal vein to visualize leukocytes in vivo and to analyze leukocyteendothelium interactions. Mice were exposed in vivo to 50 Hz linear sinusoidal wave EMF at magnetic flux densities of 3, 10 or 30 mT, for 30 minutes. Results: The mean velocity of free flowing leukocytes in the center stream of venules revealed no distinct changes following exposure. However, at a flux density of 30 mT, the number of adherent leukocytes, defined as the total number of rolling and endothelium-adhering leukocytes, increased significantly following ELFEMF exposure (p<0.05); no significant differences in adherent cell numbers were found in the 3 mT and 10 mT exposure groups or sham controls comparing pre- and post-exposure periods. Conclusion: These results demonstrated that high magnetic flux densities of ELF-EMF had an effect on leukocyte-endothelium interactions and indicated that a threshold level for this phenomenon exists in the range of 10-30 mT under these experimental conditions.