Long Wavelength Uv Radiation Affects Chemiluminescence of Human Polymorphonuclear Leucocytes

Luminol‐enhanced chemiluminescence in suspensions of human polymorphonuclear leucocytes stimulated with the chemotactic oligopeptide formyl‐methionyl‐leucyl‐phenylalanine was increased by exposure of the cells to long wavelength UV radiation (mainly320–400 nm). Leucocytes treated with 0.3 × 104 J m‐2 of UV responded with doubled peak values, and 4 × 104 J m‐2 lead to a five‐fold increase in peak chemiluminescence, as compared with non‐exposed cells. Supernatants isolated from irradiated leucocytes contained increased amounts of both myeloperoxidase and lactate dehydrogenase and showed higher chemiluminescence values, when compared with supernatants from sham‐irradiated cells. The results suggest that leucocyte degranulation contributes to the inflammatory properties of long wavelength UV.