Evidence for a role of nitric oxide in the mediation of antiproliferative UVA effects in keratinocytes
| Autor: | Hans-Peter Podhaisky, Thomas Klapperstück, Stephan Riemschneider, Wolfgang Wohlrab |
|---|---|
| Rok vydání: | 2002 |
| Předmět: |
Keratinocytes
Arginine Cell Survival Ultraviolet Rays Nitric Oxide Antioxidants Cofactor Nitric oxide Cyclic N-Oxides chemistry.chemical_compound Ultraviolet light Humans Viability assay Nitrite Cells Cultured Pharmacology omega-N-Methylarginine biology DNA synthesis Imidazoles Dose-Response Relationship Radiation DNA Free Radical Scavengers Biopterin Cytoprotection Molecular biology chemistry Biochemistry biology.protein sense organs Nitric Oxide Synthase Cell Division |
| Zdroj: | Pharmacological Research. 45:229-233 |
| ISSN: | 1043-6618 |
| Popis: | 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 μM) or the NO synthase inhibitor N(G)-monomethyl- l -arginine ( l -NMMA, 30–300 μM) 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 μM) 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. |
| Databáze: | OpenAIRE |
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