Effects of Radiofrequency Radiation at 40 kHz on Stress-Induced Immune Response in Mice

In the present study,we examined the effects of exposure to radiofrequency(RF)with intermediate frequency (IF) range at 40 kHz on immune response using a stress-induced immune suppression method and on concentrations of serum corticosterone in mice. We used antibody-forming cell (AFC) assay to evaluate the effects of RF radiation at 40 kHz on immune response in mice. The number of plaques formed by splenocytes from RS mice that were restrained and were not exposed to RF significantly decreased compared to those formed by splenocytes from control mice that were not restrained and were not exposed to RF. Thus, restraint stress induced suppression of immune response in mice. The number of plaques formed by splenocytes from RE mice that were restrained and were exposed to RF at 40 kHz increased compared to those from by splenocytes from RS mice. There was no difference in number of plaques between control and RE mice. These results showed that exposure to RF at 40 kHz improved immune suppression in restrained mice. It is well known that a variety of stresses including restraint stress result in a significant increase in stress hormones. Concentrations of corticosterone in serum of RS mice significantly increased in a restrained time-dependent manner compared to those of control mice. The concentrations of corticosterone in serum of RE mice also significantly increased in a restrained timedependent manner compared to those of control mice. There were no significant differences in concentrations of serum corticosterone between RS and RE mice. These results showed that exposure to RF at 40 kHz did not affect concentrations of serum corticosterone induced by restraint stress in mice. Therefore,the improvement of immune suppression in restrained mice by RF radiation seemed not to be directly associated with concentrations of serum corticosterone. This is the first report showing that RF radiation in a range of IF affected immune response in mice.