Generation of Active Oxygens, Cell Deformation and Membrane Potential Changes upon UV-B Irradiation in Human Blood Cells

抄録

The generation of peroxides (presumably hydrogen peroxide) by UV-B irradiation of human blood cells was detected. Non-fluorescent dihydrorhodamine 123 (DHR) is oxidized to fluorescent rhodamine 123 (R123) by H₂O₂ or peroxides with a stoichiometry of 1 : 1 in the presence of exogeneous peroxidase, and the fluorescence of R123 within the cells was measured using flow-cytometry. UV irradiation gave rise to changes in the cellular volume and the membrane potential, whose extent and direction were dependent on the type of blood cells. The production of peroxides (H₂O₂) in polymorphonuclear leukocytes is the largest among blood cells at the lower dose (<0.1J/cm²), and the production decreases with an increase in the dose, while the production in platelets is the smallest at the lower dose, but above 0.4J/cm² it increases suddently so that at the higher dose (1.2J/cm²) it amounts to 3.3×10^-16 mol/cell. For monocytes and lymphocytes, the production increases gradually with the increase in the dose.