DOSE-DEPENDENT VISIBLE EFFECT ON MICE LANGERHANS CELL-MEMBRANE MARKERS

Ultraviolet B and psoralen plus UVA treatment induce antigenic and enz ymatic changes in Langerhans cells (LC). The aim of this study was to investigate the visible (VIS) effect on mice LC surface markers. As vi sible source, a slide projector equipped with a 150-W tungsten lamp, e mitting between 400 and 740 nm (maximum at 580 nm) was used. Mice (BAL B/c and C3H) were divided into groups, each irradiated with visible si ngle fixed doses (ranging from 10 to 1000 J/cm2). The mice backs were shaved before irradiation. Skin biopsies obtained immediately after ir radiation were processed for immunofluorescence and electron microscop y. Immunofluorescent studies showed: 1) a complete depletion of LC mem brane markers at a dose of 700 J/cm2; 2) no effect at visible doses ra nging between 0 and 75 J/cm2; 3) a dose-dependent effect with doses be tween 100 and 700 J/cm 2. Electron microscopy revealed no cellular dam age of LC at the visible doses administered.