An action spectrum for the elicitation of erythema in skin persistently sensitized by photobound 8-methoxypsoralen.
Human skin can be rendered persistently photosensitive by topical application of aqueous 8-methoxypsoralen (8-MOP) and exposure to a suberythemogenic dose of more than 380 nm radiation. We report an action spectrum for the elicitation of phototoxic erythema induced by a second exposure of skin pretreated in this way. After correction for unsensitized skin erythema this action spectrum resembles the absorption spectrum of the 4',5'-monoadduct of 8-MOP to DNA. This suggests that the monoadduct is the chromophore for erythema elicited by the second irradiation, and supports the DNA crosslink as the crucial photoproduct causing phototoxic erythema due to 8-MOP in human skin.
Ortel
B
B
Wellman Laboratories of Photomedicine, Department of Dermatology, Massachusetts General Hospital, Harvard Medical School, Boston 02114.
Gange
R W
RW
D004056:Differential Threshold; D004307:Dose-Response Relationship, Radiation; D004890:Erythema / Q000139:chemically induced* / Q000209:etiology; D006801:Humans; D008027:Light; D008730:Methoxsalen; D010787:Photosensitivity Disorders / Q000139:chemically induced*; D013997:Time Factors; D014466:Ultraviolet Rays / Q000009:adverse effects
D008730:Methoxsalen