Subcutaneous Arteriolar Vasomotion Changes During and After ELF-EMF Exposure in Mice in Vivo
- 58 Downloads
Biological effects of extremely low-frequency electromagnetic fields (ELF-EMF) on microcirculation were investigated in vivo by monitoring arteriole diameters in conscious mice. Measurements of blood vessel diameter were monitored 33 min non-stop before during and after exposure with ELF-EMF and every 389 ms blood vessel diameter were calculated.
Using a dorsal skinfold chamber (DSC), and following caudal vein injection of FITC-dextran 250 kDa, the microvasculature (initial arteriole diameter of 45–80 μm), was examined by intravital microscopy and video images were recorded for a total time of 33 min. Arteriole diameter was continuously measured by on-line analysis using a High-speed Digital Machine Vision System CV-2100, using an edge-gap detection algorithm. Since vessel diameters exhibit rhythmic variation expressed by vasomotion, for estimation of microcirculatory activity we used both raw data for frequency analysis of vasomotion (measured frequencies of vasomotion were in the range 0.008÷0.1 Hz) and evaluate mean blood vessel diameter for each 1 min period of time, and make a comparison between Pre, Exposure/Sham exposure and Post exposure periods, with the aim to evaluate possible changes in mean blood vessel diameter as a result of ELF-EMF action.
During EMF exposure and post-exposure periods, arteriole diameters increased significantly compared with the pre-exposure period, and the changes were larger during post-exposure. In contrast to sham exposure, vasodilatation of the microvasculature was significantly greater during exposure and post-exposure to 16 Hz EMF. These findings suggest that ELF-EMF may have potential therapeutic use benefit for treating vascular disorders.
KeywordsELF-EMF microcirculation blood vessel diameter skin
Unable to display preview. Download preview PDF.
- Aalkjaer, C. and Nilsson, H.: 2005, “Vasomotion: Cellular Background for the Oscillator and for The Synchronization of Smooth Muscle Cells,” Br J Pharmacol. (Epub ahead of print) 1–24.Google Scholar
- Colantuoni, A., Bertuglia, S., Coppini, G. and Donato, L.: 1990, “Superposition of Arteriolar Vasomotion Waves and Regulation of Blood Flow in Skeletal Muscle Microcirculation,” Adv Exp Med Biol 277, 549–558.Google Scholar
- Ichioka, S., Iwasaka, M., Shibata, M., Harii, K., Kamiya, A. and Ueno, S.: 1998, “Biological Effects of Static Magnetic Fields on the Microcirculatory Blood Flow In Vivo: A Preliminary Report,” Med Biol Eng Comput. 36(1), 91–95.Google Scholar
- Geyer, M.J., Yih-Kuen, J., Brienza, D.M. and Boninger, I.L.: 2004, “Using Wavelet Analysis to Characterize the Thermoregulatory Mechanisms of Sacral Skin Blood Flow,” Journal of Rehabilitation Research & Development 41(6A), 797–806.Google Scholar
- Johansson, B. and Mellander, S.: 1975, “Static and Dynamic Changes in the Vascular Myogenic Response to Passive Changes in Lenght as Revealed by Electrical and Mechanical Recording from the Rat Portal Vein,” Circulation Research 36(1), 76–83.Google Scholar
- Johnson, P.C.: 1986, “Autoregulation of Blood Flow,” Circulation 59(1), 483–495.Google Scholar
- Lednev, V.V.: 1991, “Possible Mechanism for the Influence of Weak Magnetic Fields on Biological Systems,” Bioelectromagnetics 12(2), 71–75.Google Scholar
- Liboff, A.R. and Parkinson, W.C.: 1991, “Search for Ion-Cyclotron Resonance in an Na(+)-Transport System,” Bioelectromagnetics 12(2), 77–83.Google Scholar
- Loschinger, M., Thumm, S., Hammerle, H. and Rodemann, H.P.: 1999, “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,” Radiat Res. 151(2), 195–200.Google Scholar
- Maruyama, S. and Ohkubo, C.: 1994, Acute Effects of Static Magnetic Fields and Extremely Low Frequency Electromagnetic Fields on Cutaneous Microcirculation in Rabbits (Part2), Tokyo: Nihon-Igakukan, Tokyo.Google Scholar
- Ohkubo, C. and Xu, S.: 1997, “Acute Effects of Static Magnetic Fields on Cutaneous Microcirculation in Rabbits,” in vivo 11(3), 221–225.Google Scholar
- Ohkubo, C., Gmitrov, J., Xu, S. and Nakayama, E.: 1997, Vasodilator Effects of Static Magnetic Fields on Cutaneous Microcirculation Under Increased Vascular Tone in the Rabits, Tokyo: Nihon-Igakukan, Tokyo.Google Scholar
- Okano, H. and Ohkubo, C.: 1998, Vasoconstrcting Effects of Static Magnetic Fields on Cutaneous Microcirculation Under Decreased Vascular Tone in the Rabbit, Tokyo: Nihon-Igakukan, Tokyo.Google Scholar
- Okano, H., Gmitrov, J. and Ohkubo, C.: 1999, “Biphasic Effects of Static Magnetic Fields on Cutaneous Microcirculation in Rabbits,” Bioelectromagnetics 20(1), 161–171.Google Scholar
- Sander, D., Meyer, B.U., Roricht, S., Matzander, G. and Klingelhofer, J.: 1996, “Increase of Posterior Cerebral Artery Blood Flow Velocity During Threshold Repetitive Magnetic Stimulation of the Human Visual Xortex: Hints for Neuronal Activation Without Cortical Phosphenes,” Electroencephalogr Clin Neurophysiol. 99(5), 473–478.Google Scholar
- Takeshige, C. and Sato, M.: 2004, “Comparisons of Pain Relief Mechanisms Between Needling to the Muscle, Static Magnetic Field, External Qigong and Needling to the Acupuncture Point,” Acupunct Electrother Res. 21(2), 119–131.Google Scholar
- Xu. S., Okano, H. and Ohkubo, C.: 2000, “Acute Effects of Whole-Body Exposure to Static Magnetic Fields and 50-Hz Electromagnetic Fields on Muscle Microcirculation in Anesthetized Mice,” Bioelectrochemistry 53(1), 127–135.Google Scholar