SUMMARY
This study aimed to examine the effects of short and long term
exposures to 81 mG EMF intensity. It focused on the roles ofROS,
Ca2+ and calcium channel blocker (CCB) on the rat brain. Rats were
exposed to 81 mG EMF intensity at the mobile phone base station for
one and four weeks (2 hr/day, EMF exposed group). Another group of
rats was pretreated with CCB (amlodipine 20 mg/ kg) for four weeks
and similarly exposed to EMF (EMF + amlodipine group). Sham exposed
and amlodipinecontrol groups were used. At the end of the study,
Ca2+ as well as pro-inflammatory and oxidative stress markers were
measured. Immunohistochemical staining for Bax in brain samples was
carried out. Short term exposure evoked a cellular adaptation
response. This was evident by a transient increase in brain levels of
Ca2+, glutathione (GSH) and serum tumor necrosis factor alpha
(TNFalpha). Long term exposure to EMF was lethal; progressive oxidative
damage, and a prolonged increase in the Ca2+ levelaccompanied by a
marked pro-inflammatory reaction (TNFalpha and CRP) were demonstrated.
These alterations were ameliorated by pre- and con-comitant treatment
with amlodipine. Furthermore, it restored the EMF induced apoptosis
in brain tonear normal. In conclusion, EMF is a stressor agent that
induces an imbalance between ROS generation and antioxidant defense
response. Calcium ions may play a pivotal role in enhancing oxidative
stress, pro-inflammatory reactions and apoptosis associated with EMF
exposure. Therefore calcium channel blockade seems to play a role in
brain protection.
KEY WORDS
electromagnetic field; calcium; oxidative stress; apoptosis; amlodipine; rats
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Kovacic P, Somanathan R. Electromagnetic fields: mechanism, cell signaling, other bioprocesses, toxicity, radicals, antioxidants and beneficial effects. J
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