RESUMO
Environmental factors such as electromagnetic fields influence the pain sensation. To investigate the possible analgesic effect of extremely low frequency electromagnetic fields [ELF-EMFs] exposure and possible interaction between ELF-EMFs and opioid, alpha and beta adrenergic systems. This was an experimental study in which the effect of 60 Hz magnetic field [100mT] on the pain threshold of 80 male albino mice was investigated. Pain threshold was assessed by the tail immersion technique using water with a temperature of 52 C. The mean pain threshold was significantly increased in case group [5.85 +/- 0.69 sec] compared to control group [3.77 +/- 0.55 sec] following ELF-EMF exposure [p<0.0001]. Pretreatment of animals with naloxane [2 mg/kg] and phentolamine [10 mg/kg] significantly reduced the effect to [3.97 +/- 0.7 sec and 4.01 +/- 0.49 sec], respectively [p<0.0001]. There was no change in the value of mean pain threshold [5.77 +/- 0.68 sec] when propranolol [10 mg/kg] was administered [p<0.0001]. Based on our data, exposure to ELF-EMFs could induce analgesic behavior in mice and the associated effect is related to opioid and alpha-adrenergic systems