Effects of far-infrared ray on reproduction, growth, behaviour and some physiological parameters in mice

The effects of chronic exposure to far-infrared ray (FIR) on reproduction, growth, behaviour, survival time and some related parameters were examined in SHN mice. The reproductive parameters differed slightly between the females on the normal racks and those on the FIR racks, which emitted FIR from the ceiling. The age and body weight on the day of vaginal opening was lower in the experimental mice born and maintained on the FIR rack than in the control on the normal rack. In both sexes, the levels of urinary components in the experimental group was significantly higher than the control at 6-7 months of age. Spontaneous motor activity of females during the light and dark phases were higher and lower, respectively, in the experimental group than the control. The survival rate was significantly higher in the experimental group than the control. These findings suggest that FIR has 'normalization effects' on the organisms.