Low-Power Laser Irradiation Induces Leukocyte Priming

Lasei ladiation (LR) of vanous spectial composition has been bioadl-y used m c hnual piactice Howevei the mechanism of the stimulating effects of LR icmams obscuie The effect of He-Ne LR (633 nm) on human blood leukocytes was investigated both m the absence and presence of 8 65 nmol/1 phthalocyanme (PhC) Inadiation of non-stimulate d leukocytes with 0 025 to 0 5 I/cm- did not lead to anv activation of their lummol-dependent cheimluminescence (LCL) On the othei hand LR mc leased m most cases the subsequent CL response of the cells to opsonized 7\mosan (pinning action of He-Ne-lasei light) The effect of LR on the leukoc\tes was not standard In niadiated leukocytes isolated from patients with se\eie acute oi chiomc pneumonia oi chiomc bi one hit is the maximal LCL exceeded that foi non-inadiated cells b\ 80% (0 05 I/cur) 20 25% (0 15 J/cnr), and 0%, iespectively (doses are shown m paientheses) Fuither increase of the ex posuie bi ought about a dose-dependent inhibition of LCL m cells from patients with severe acute and chronic pneumonia There was an mtngumg relationship between maximal CL responses of leukocytes subjected to lasei irradiation m the piesence and without PhC When the piiming effect of LR on isolated cells was small it incieased m the piesence of exogenous photosensitizer, phthalocyanme, m cells of sc\eieh ill patients wheie the initial effect of LR was strong Pc inhibited the pinning ac tion of LR Apparently, diffeient cells contained diffeient amounts of endogenous photosensitizer(s), the addition of exogenous sensitizei increased the pnmnig action of LR at low concentrations and deaeased it at higher concentra­ tions of the endogenous photosensitize!