Biochemical observations in UV-induced pigmentation.
The biochemical events in the melanocytes resulting from stimulation of pigmentation by exposure to ultraviolet (UV) irradiation are correlated to changes in specific metabolites in the plasma and in the urine. A compound produced in the melanocyte by nucleophilic addition of cysteine to dopaquinone, 5-S-cysteinyldopa, is present in increased quantities in the plasma and in the urine after different types of pigment-producing UV exposure. Similarly, a methylated indolic metabolite, 6-hydroxy-5-methoxyindole-2-carboxylic acid, appears in increased amounts in the urine after UV exposure of the skin. UVA does not produce inflammation or pigmentation in skin that is anoxic at the time of irradiation. In contrast, inflammation and pigment response to UVB and PUVA are not dependent on oxygenation of the skin at the time of exposure.
Rorsman
H
H
Department of Dermatology, University of Lund, Sweden.
Tegner
E
E
D003548:Cysteinyldopa / Q000378:metabolism; D006801:Humans; D000860:Hypoxia; D007211:Indoles / Q000652:urine; D008544:Melanocytes / Q000378:metabolism / Q000528:radiation effects; D011701:PUVA Therapy; D012880:Skin Pigmentation / Q000528:radiation effects*; D014466:Ultraviolet Rays
D007211:Indoles; D003548:Cysteinyldopa; C017408:6-hydroxy-5-methoxy-2-indolylcarboxylic acid