The electromagnetic fields (EMFs) have been shown to alter animal and human behavior, such as directional orientation, learning, pain perception (nociception or
analgesia) and anxiety-related behaviors. The aim of this study was to evaluate the influence of electromagnetic fields of high-frequency microwaves on pain perception and anti-nociceptive activity of
tramadol (TRAM) - analgetic effective in the treatment of moderate to severe acute and
chronic pain states. Electromagnetic fields exposures of a)1500 MHz frequency and b) modulated, 1800 MHz (which is identical to that generated by mobile phones) were applied. Paw withdrawal latency (PWL) to thermal stimulus was measured in vehicle or
tramadol (TRAM) treated animals before and after 30, 60 and 90 minutes from
injections. The differences in the level of
pain (PWL) between control group and rats exposed to EMF alone in three measurements, were not observed.
Tramadol alone significantly increased PWLs to thermal stimulus in comparison to vehicle results at 30 (p < 0.001) and 60 minutes (p < 0.05) after
drug injection. EMF exposure of both frequencies transiently suppressed
analgesic effect of
tramadol, significantly reducing paw withdrawal latency in animals treated with this
drug at 30 minutes from the
drug injection.