| Autor: |
de Laat, J.M.T., Seite, S., Groenendijk, M., Van Vloten, W.A., De Gruijl, E.R. |
| Předmět: |
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| Zdroj: |
Experimental Dermatology; Dec97, Vol. 6 Issue 6, p292-297, 6p |
| Abstrakt: |
In a study on the dose response relationship for longwave UVA (UVAI: 300 400nm) carcinogenesis in hairless mice scratch marks appeared after months of daily exposure as an unwanted side effect. Tumor induction in the highest of 4 tested dose groups (receiving a daily dose of 430 k.l/m[SUP2] of 365-nm radiation) could not be determined because extensive scarification occurred prior to the development of any tumors. The induction of scratch marks could be scored and quantified in all 4 dose groups tested. The UVAI dose-dependencies for the induction of tumors and scratch marks were compared. We found that the induction of scratch marks depended mainly on the cumulative UVAI exposure, whereas tumor induction showed a lesser dose-dependency. An attempt was made to prevent the apparent pruritogenic effect of UVAI irradiation and to understand its mechanism. The influence of ketanserin, a scrotonin/histamine antagonist, on the UVAI induction of scratch marks was tested in groups of 8 mice daily irradiated with 430 k.l/m[SUP2]. No difference was found between from treated and untreated animals. Histological examination of skin biopsies from irradiated mice from the 430 k.l/m[SUP2] dose group from the UVAI carcinogenic expriment, showed no changes in numbers of mast cells or other inflammatory features when compared to skin biopsies from unirradiated control mice. This indicated that UVAI-induced scratching is not mediated through mast cell release of serotonin and/or histamine. An adequate therapeutic treatment which can prevent UVAI-induced scratching would enable us to test tumor induction with UVAI over a larger dose range, and may provide additional insight in how this radiation damages the skin. It remains conjectural whether there exists an analogous UVA-induced pruritus in human skin. [ABSTRACT FROM AUTHOR] |
| Databáze: |
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