Evidence for a role of nitric oxide in the mediation of antiproliferative UVA effects in keratinocytes.
Pharmacol Res
; 45(3): 229-33, 2002 Mar.
Article
em En
| MEDLINE
| ID: mdl-11884220
ABSTRACT
Using cultured human keratinocytes, the present study investigates the role of nitric oxide (NO) in the mediation of the antiproliferative effects of ultraviolet light A (UVA). UVA treatment of cells (3-21 J cm (-2)) caused a time- and dose-dependent increase in nitrite formation in a micromolar range. This effect was accompanied by a decrease in DNA synthesis by 53.5%. Moreover, UVA treatment slightly reduced cell viability by 23.8%. Preincubation of keratinocytes with the NO scavenger 4,4,5,5-tetramethyl-imidazoline-1-oxyl-3-oxide (PTIO, 10-100 microM) or the NO synthase inhibitor N(G)-monomethyl-l-arginine (l-NMMA, 30-300 microM) significantly diminished the UVA-induced increase in nitrite. PTIO as well as l-NMMA partially protected keratinocytes from UVA-induced antiproliferative effects and increased DNA synthesis by 67 or 49% of the control. The co-application of UVA irradiation (10 J cm (-2)) and the essential cofactor of NO synthases tetrahydrobiopetrin (BH4, 500 microM) led to an overadditive increase in the release of nitrite as well as to a decrease in DNA synthesis. These results imply that NO is involved in the antiproliferative UVA effects in keratinocytes.
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Coleções:
01-internacional
Base de dados:
MEDLINE
Assunto principal:
Raios Ultravioleta
/
Biopterinas
/
Queratinócitos
/
Óxido Nítrico
Limite:
Humans
Idioma:
En
Revista:
Pharmacol Res
Assunto da revista:
FARMACOLOGIA
Ano de publicação:
2002
Tipo de documento:
Article
País de afiliação:
Alemanha
País de publicação:
HOLANDA
/
HOLLAND
/
NETHERLANDS
/
NL
/
PAISES BAJOS
/
THE NETHERLANDS