Schothorst A A, Evers L M, Noz K C, Filon R, van Zeeland A A
Department of Dermatology, University Hospital Leiden, The Netherlands.
J Invest Dermatol. 1991 Jun;96(6):916-20. doi: 10.1111/1523-1747.ep12475443.
We compared the susceptibilities of cultured melanocytes and keratinocytes to dimer induction in DNA by monochromatic ultraviolet (UV) radiation. Keratinocytes as well as melanocytes were derived from human foreskin, grown as a monolayer in petri dishes, covered with phosphate-buffered saline containing 0.1% glucose, and irradiated. UV irradiation was carried out at 254, 297, and 302 nm as well as with a light source emitting predominantly 312 nm. The induction of pyrmidine dimers was assessed by determination of the number of T4 endonuclease V-sensitive sites (ESS). We found a slightly higher response for dimer induction in melanocytes at 254, 297, and 302 nm; this difference was only significant at the 297-nm wavelength. Action spectra for pyrimidine dimer induction were derived from the exposure-response data obtained. The action spectra mimic to a large degree the action spectra for dimer induction in other cultured mammalian cells. The repair rate during a post-irradiation period lasting up to 24 h was substantially the same for the two cell types. The percentage of T4 endonuclease V-sensitive sites (ESS) remaining 9 and 24 h after irradiation was 45% and 30%, respectively.
我们比较了培养的黑素细胞和角质形成细胞对单色紫外线（UV）辐射诱导DNA形成二聚体的敏感性。角质形成细胞和黑素细胞均取自人包皮，在培养皿中单层生长，覆盖含0.1%葡萄糖的磷酸盐缓冲盐水，然后进行辐照。紫外线辐照分别在254、297和302纳米波长下进行，以及使用主要发射312纳米的光源进行。通过测定T4核酸内切酶V敏感位点（ESS）的数量来评估嘧啶二聚体的诱导情况。我们发现，在254、297和302纳米波长下，黑素细胞中二聚体诱导的反应略高；这种差异仅在297纳米波长处显著。嘧啶二聚体诱导的作用光谱源自所获得的暴露-反应数据。该作用光谱在很大程度上模仿了其他培养的哺乳动物细胞中二聚体诱导的作用光谱。两种细胞类型在长达24小时的辐照后修复率基本相同。辐照后9小时和24小时剩余的T4核酸内切酶V敏感位点（ESS）百分比分别为45%和30%。
