Reduction in eumelanin by the activation of glutathione reductase and ?-glutamyl transpeptidase after exposure to a depigmenting chemical.
Yonemoto-K; Gellin-GA; Epstein-WL; Fukuyama-K
Biochem Pharmacol 1983 Apr; 32(8):1379-1382
Experiments were designed to test whether any correlation exists between the enzyme activities involving reduced glutathione (GSH) and cysteinyldopa formation and the eumelanin and sulfur contents of tissue cultured human melanoma cells, M3, following exposure to 4- tertiary-butyl-catechol (98293) (TBC). At day six of culture, M3 cells were incubated for 2 hours in media containing 10(-4) molar TBC or in media containing 0.1 percent dimethyl-sulfoxide. Enzyme activities were unchanged during the first 6 hours after treatment with TBC, however, by 42 hours after treatment, both glutathione- reductase (GR) and gamma-glutamyl-transpeptidase (GGTP) activities were increased. TBC had no apparent effect on eumelanin content up to 24 hours after treatment, but caused a reduction in the increase of the eumelanin content by 42 hours after treatment. Macroscopic examination of pelleted cells revealed a significant lightening of the cell color following TBC treatment. An increase in sulfur content was also observed in the TBC exposed cells. The authors conclude that the detection of increased GR and GGTP activities indicates a shift in melanogenesis toward sulfur rich melanins. Modulation of the melanocyte function occurs following TBC exposure, resulting in a reproducible and time dependent change in specific enzyme activity and the induction of pheomelanin synthesis.
NIOSH-Publication; NIOSH-Grant; Dermatitis; Enzyme-activity; Cell-damage; Pigmentation-disorders; Biochemistry; In-vitro-studies; Cell-cultures; Mammalian-cells
Dermatology University of California Department of Dermatology San Francisco, Calif 94143
University of California San Francisco, San Francisco, California