title: Interaction of ultraviolet-B-rich and ultraviolet-A-rich radiation in ketoprofen-induced photohemolysis.
abstract: Interactions between different wavelengths can cause inhibition or enhancement of various biological reactions. We evaluated in vitro the effect of UVB-rich irradiation on UVA-induced phototoxicity. Suspensions of human erythrocytes were incubated with ketoprofen, a phototoxic nonsteroidal anti-inflammatory drug. These samples were exposed to 0, 20, 40, 80, 160 or 320 mJ/cm2 UVB followed by irradiation with 0 or 6 J/cm2 UVA. Photo-induced hemolysis was calculated as a percentage of complete hemolysis. Ketoprofen-dependent hemolysis due to UVA alone was 63% (median). UVB did not induce ketoprofen-dependent photohemolysis at doses < 80 mJ/cm2. Exposure to UVB at all doses enhanced significantly (P < 0.01) UVA-induced ketoprofen-dependent hemolysis in samples from 9 of 15 donors. However, with erythrocytes from the other 6 donors, 20 or 40 mJ/cm2 UVB reduced the median of UVA-induced photohemolysis by 69% (P < 0.05) or 47% (not significant), respectively. Co-incubation of samples with ascorbic acid resulted in a profound inhibition of ketoprofen-dependent photohemolysis. These results indicate that the effect of low UVB doses on UVA-induced phototoxicity depends on individual, yet unknown characteristics of the target cells.
authors.affiliation: Dermatologische Klinik und Poliklinik, Ludwig-Maximilians-Universität, Munich, Germany.
authors.forename: B
authors.initials: B
authors.lastname: Eberlein-König
authors.forename: F
authors.initials: F
authors.lastname: Rueff
authors.forename: B
authors.initials: B
authors.lastname: Przybilla
mesh_terms: D000293:Adolescent; D000328:Adult; D000894:Anti-Inflammatory Agents, Non-Steroidal / Q000494:pharmacology*; D004912:Erythrocytes / Q000187:drug effects / Q000528:radiation effects; D005260:Female; D006461:Hemolysis / Q000187:drug effects* / Q000528:radiation effects*; D006801:Humans; D066298:In Vitro Techniques; D007660:Ketoprofen / Q000494:pharmacology*; D008297:Male; D008875:Middle Aged; D014466:Ultraviolet Rays
chemical_list: D000894:Anti-Inflammatory Agents, Non-Steroidal; D007660:Ketoprofen