Summary
Mammalian cells were exposed to ultraviolet light and the incorporation of labelled DNA precursors was studied. Irradiation caused stimulated incorporation of pyrimidine precursors in cells in which normal DNA synthesis was suppressed byhydroxyurea. This occurred also in non S-phase cells and has been ascribed to a repair process of photochemical damage in DNA. Substitution of thymine bases by bromouracil promoted repair incorporation of labelled thymidine as well as deoxycytidine. A modification of current theories on the sensitizing action of bromouracil in UV irradiated cells is discussed.
Zusammenfassung
SÄugetierzellen in Gewebekultur wurden mit ultraviolettem Licht bestrahlt und der Einbau von markierten DNS-Bausteinen gemessen. Die Bestrahlung verursachte eine Hemmung der DNS-Synthese, dagegen eine Stimulierung des Einbaus von markierten Pyrimidin-Desoxyribonucleosiden in Zellen, die normalerweise keine Synthese von DNS aufweisen. Die teilweise Ersetzung von Thymin durch Bromuracil führte nach Bestrahlung zu einer verstÄrkten Stimulierung des Einbaus von Thymidin als auch von Desoxycytidin. Die Ergebnisse weisen auf eine Reparatur von UV-SchÄden in der DNS hin. Eine Erweiterung bestehender Auffassungen über die Strahlensensibilisierung durch Bromuracil wurde diskutiert.
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Smets, L.A. Repair incorporation of pyrimidine deoxynucleosides into DNA of mammalian cells exposed to UV light. Biophysik 6, 85–93 (1969). https://doi.org/10.1007/BF01195904
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DOI: https://doi.org/10.1007/BF01195904