Effect of linear polarized near-infrared ray irradiation on the chemiluminescence of human neutrophils and serum opsonic activity

The purpose of this study was to investigate the in vitro effects of Linear polarized near-infrared ray irradiation on neutrophil chemiluminescence (C L) and serum opsonic activity. We used luminol- and lucigenin-dependent CL to detect the affected reactive oxygen species production process of human neutrophils and measured serum opsonic activity based on luminol-dependent CL. The linear polarized near-infrared ray irradiation suppressed a maximum light emission (peak height) of luminol- and lucigenin-dependent CL in a d ose-dependent manner. The findings suggested that, the linear polarized nea r-infrared ray irradiation suppressed the superoxide anion and hypochlorite production of human neutrophils. The serum opsonic activity was decreased by linear polarized near-infrared ray irradiation, and this suppressive eff ect might be caused by inhibiting the activation of the classical and alter native complement pathway. Therefore, it is suggested that near-infrared ra y irradiation may have an inhibitory effect against chronic pain via reduct ion of reactive oxygen species production and opsonic activity. Copyright ( C) 1999 John Wiley & Sons, Ltd.