Abstract |
Dopac increases tyrosinase activity and exerts cytotoxic effects in cultures of human melanoma cells. The possible role of hydrogen peroxide in these actions was examined. Catalase (100 micrograms/ml) completely reversed the cytotoxic action of 0.3 mM dopac and reduced its tyrosinase-stimulating effect by approximately one half. The results show that extracellular hydrogen peroxide is a mediator of both the tyrosinase-stimulating and cytotoxic actions of dopac. Analysis of the degradation products of melanin from dopac-treated melanoma cells after hydriodic acid (HI) hydrolysis revealed the presence of aminohydroxy- phenylacetic acid (AHPAc). This substance is obtained by HI hydrolysis of melanin formed by oxidation of cysteinyl- dopac. Thus, the presence of AHPAc indicates that dopac is transported into the melanocytes where it serves as a substrate for tyrosinase.
|
Authors | E Karg, E Rosengren, H Rorsman |
Journal | The Journal of investigative dermatology
(J Invest Dermatol)
Vol. 96
Issue 2
Pg. 224-7
(Feb 1991)
ISSN: 0022-202X [Print] United States |
PMID | 1899444
(Publication Type: Journal Article, Research Support, Non-U.S. Gov't)
|
Chemical References |
- Melanins
- Phenylacetates
- 3,4-Dihydroxyphenylacetic Acid
- 4-amino-3-hydroxyphenylacetic acid
- Levodopa
- Hydrogen Peroxide
- Catalase
- Monophenol Monooxygenase
|
Topics |
- 3,4-Dihydroxyphenylacetic Acid
(pharmacology)
- Catalase
(pharmacology)
- Cell Line
- Humans
- Hydrogen Peroxide
(metabolism, pharmacology)
- Levodopa
(pharmacology)
- Melanins
(metabolism)
- Melanoma
- Monophenol Monooxygenase
(metabolism)
- Phenylacetates
(analysis, chemical synthesis)
|