The effect of prolong exposure to low frequency electromagnetic fields on mechanical activity of isolated aorta of male rats

Background: Electromagnetic fields (EMF) have been proposed to affect cardiovascular system. This study was designed to assess the effects of long term exposure of extremely low frequency EMF of 100 and 500 µT on vascular activity in rats .Methods: Twenty one Wistar adult male rats were divided equally into three groups. The first group exposed to 50 Hz, 100 µT (EMF-100), another group exposed to 50 Hz, 500 µT (EMF-500), and the third group were consider as control and were not exposed to EMF. After 210 days of exposure, The animals were anaesthetized and thoracic aorta preparation was dissected and cut into 5 mm strips were linked to force transducer that connected to AD instrument powerlab. The aortic strips inserted to organ bath chambers containing oxygenated Krebs solution (37 °C). Then the aortic isometric tension was recorded after phenylephrine and acetylcholine administration.Results: Vasorelaxation response to acetylcholine was not significantly different between three groups (p=0.60). However, the vasoconstriction response to phenylephrine in 500 µT group was less than those of other groups (p=0.035).Conclusion: It seems that prolong exposure to LF- EMF alter vascular response to vasoactive factors via adrenergic receptor pathways.