To examine the sensitivity of vitiligo melanocytes to external oxidative stress, we studied enzymatic and non-enzymatic anti-oxidants in cultured melanocytes of normal subjects (n = 20) and melanocytes from apparently normal skin of vitiligo patients (n = 10). The activity of superoxide dismutase and catalase and the intracellular concentrations of vitamin E and ubiquinone were evaluated in cultures at the fourth or fifth passage, In addition, cells were exposed to various concentrations of a peroxidizing agent, cumene hydroperoxide (CUH, 0.66-20 mu M), for 1 and 24 h, Compared to normal melanocytes, vitiligo melanocytes showed normal superoxide dismutase and significantly lower catalase activities and higher vitamin E and lower ubiquinone levels. At the concentration used, CUH did not significantly affect cell number or viability of melanocytes after either period of culture, On the contrary, vitiligo melanocytes were susceptible to the toxic effect of CUH after 24 h of continuous treatment at concentrations greater than 6.6 mu M. The degree of CUH toxicity correlated strictly with the anti-oxidant pattern, defined as the ratio between vitamin E concentration and catalase activity, suggesting chat the alteration in the antioxidants was the basis for sensitivity to the external oxidative stress, Our results demonstrate the presence of an imbalance in the anti-oxidant system in vitiligo melanocytes and provide further support for a free radical-mediated damage as an initial pathogenic event in melanocyte degeneration in vitiligo.

Increased sensitivity to peroxidative agents as a possible pathogenic factor of melanocyte damage in vitiligo / Vittoria, Maresca; Maria, Roccella; Francesca, Roccella; Emanuela, Camera; Giuseppe Del, Porto; Siro, Passi; Grammatico, Paola; Mauro, Picardo. - In: JOURNAL OF INVESTIGATIVE DERMATOLOGY. - ISSN 0022-202X. - STAMPA. - 109:3(1997), pp. 310-313. [10.1111/1523-1747.ep12335801]

Increased sensitivity to peroxidative agents as a possible pathogenic factor of melanocyte damage in vitiligo

GRAMMATICO, Paola;
1997

Abstract

To examine the sensitivity of vitiligo melanocytes to external oxidative stress, we studied enzymatic and non-enzymatic anti-oxidants in cultured melanocytes of normal subjects (n = 20) and melanocytes from apparently normal skin of vitiligo patients (n = 10). The activity of superoxide dismutase and catalase and the intracellular concentrations of vitamin E and ubiquinone were evaluated in cultures at the fourth or fifth passage, In addition, cells were exposed to various concentrations of a peroxidizing agent, cumene hydroperoxide (CUH, 0.66-20 mu M), for 1 and 24 h, Compared to normal melanocytes, vitiligo melanocytes showed normal superoxide dismutase and significantly lower catalase activities and higher vitamin E and lower ubiquinone levels. At the concentration used, CUH did not significantly affect cell number or viability of melanocytes after either period of culture, On the contrary, vitiligo melanocytes were susceptible to the toxic effect of CUH after 24 h of continuous treatment at concentrations greater than 6.6 mu M. The degree of CUH toxicity correlated strictly with the anti-oxidant pattern, defined as the ratio between vitamin E concentration and catalase activity, suggesting chat the alteration in the antioxidants was the basis for sensitivity to the external oxidative stress, Our results demonstrate the presence of an imbalance in the anti-oxidant system in vitiligo melanocytes and provide further support for a free radical-mediated damage as an initial pathogenic event in melanocyte degeneration in vitiligo.
1997
catalase; free radicals; oxidative stress; superoxide dismutase; ubiquinone; vitamin e
01 Pubblicazione su rivista::01a Articolo in rivista
Increased sensitivity to peroxidative agents as a possible pathogenic factor of melanocyte damage in vitiligo / Vittoria, Maresca; Maria, Roccella; Francesca, Roccella; Emanuela, Camera; Giuseppe Del, Porto; Siro, Passi; Grammatico, Paola; Mauro, Picardo. - In: JOURNAL OF INVESTIGATIVE DERMATOLOGY. - ISSN 0022-202X. - STAMPA. - 109:3(1997), pp. 310-313. [10.1111/1523-1747.ep12335801]
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Utilizza questo identificativo per citare o creare un link a questo documento: https://hdl.handle.net/11573/118064
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