title: Stimulation of pigmentation in melanoma cells by trimethylpsoralen in the absence of ultraviolet irradiation.
abstract: The effects of trimethylpsoralen and 8-methoxypsoralen on the pigmentary characteristics of cultured murine melanoma cells were investigated in the absence of ultraviolet irradiation. Stimulation of pigmentation was assayed by gross examination of centrifuged cell pellets, light microscopy of cells, electron microscopy, a biochemical determination of cell tyrosinase activity, and a chemical determination of cell melanin content. It was found that an adequate concentration (10(-5) M) of trimethylpsoralen for an adequate exposure time stimulated pigmentation in the dark, whereas 8-methoxypsoralen in the same experimental setting did not stimulate pigmentation.
mesh_terms: D000818:Animals; D002460:Cell Line; D003624:Darkness; D011564:Furocoumarins / Q000494:pharmacology*; D008545:Melanoma / Q000503:physiopathology* / Q000648:ultrastructure; D008730:Methoxsalen / Q000494:pharmacology; D051379:Mice; D008854:Microscopy, Electron; D009374:Neoplasms, Experimental / Q000503:physiopathology; D010858:Pigmentation / Q000187:drug effects*; D013268:Stimulation, Chemical; D013997:Time Factors; D014307:Trioxsalen / Q000494:pharmacology*
chemical_list: D011564:Furocoumarins; D008730:Methoxsalen; D014307:Trioxsalen