title: Mutagenicity of 8-methoxypsoralen and long-wave ultraviolet irradiation in V-79 Chinese hamster cells. A first approach to a risk estimate in photochemotherapy.
abstract: The effect of 8-methoxypsoralen (8-MOP) and long-wave ultraviolet irradiation (UVA) on cell killing and mutation induction was studied in V-79 Chinese hamster cells. No effect was observed after treatment with 8-MOP alone (50 microgram/ml, 4 h), UVA alone (9000 J/m2), or 8-MOP metabolized by rat-liver microsomes. Combined treatment with 8-MOP and UVA induced both cell killing and mutation. This was also observed under conditions approaching patient treatment with PUVA photochemotherapy with respect to the concentration of 8-MOP in the skin and the amount of UVA received by the epidermal cells. A simple relation proved to apply for mutation induction under different treatment conditions: 5.5 X 10(-8) per J/m2 per microgram 8-MOP/ml. On this basis the mutation induction in dividing cells per session of PUVA-photochemotherapy amounts to 12.4 X 10(-5), which is probably an over-estimation.
mesh_terms: D000818:Animals; D002460:Cell Line / Q000528:radiation effects*; D006224:Cricetinae; D008730:Methoxsalen / Q000494:pharmacology*; D009153:Mutagens; D010778:Photochemotherapy; D012306:Risk; D012871:Skin Diseases / Q000188:drug therapy; D014466:Ultraviolet Rays
chemical_list: D009153:Mutagens; D008730:Methoxsalen