EFFECTS OF RED LIGHT AT 640 nm FROM LIGHT EMITTING DIODES ON THE RESPIRATORY BURST OF HUMAN NEUTROPHILS

Abstract

Photobiomodulation (PBM) has been reported to have effects on respiratory burst of polymorphonuclear neutrophils (PMNs), but little focus was on the individual differences of human PMNs. The latter was investigated in this study. The PMNs were isolated from peripheral blood of 13 volunteers (10 ordinary persons, 3 athletes) and treated by red light (640 ± 15 nm) from light emitting diodes (RLED) at 50, 100, 300, 500 and 1000 J/m2 for 100 seconds, respectively. Blood samples of athletes were extracted at different running stages in 10 km non-interrupted long-distance running, before running, 1 hour after running began, just finishing the running, resting for 1 hour and 2 hours after running. The PMN respiratory burst was assessed by the nitroblue tetrazolium test. It was found that there were three types of RLED PBM on the respiratory burst of 3 types of PMNs, respectively, inducing for the subactivated PMNs, inhibiting for the overactivated PMNs and none for the PMNs in homeostasis. It was then concluded that there may be RLED PBM on dysfunctional human PMNs while none on those in homeostasis, and RLED at 300 J/m2 for 100 seconds may have bi-direction modulation on PMN respiratory burst.