de Leeuw S M, Janssen S, Simons J W, Lohman P H, Vermeer B J, Schothorst A A
Department of Dermatology, University Hospital Leiden, The Netherlands.
Photochem Photobiol. 1994 Apr;59(4):430-6. doi: 10.1111/j.1751-1097.1994.tb05060.x.
Melanocytes (skin type 2) and keratinocytes were irradiated with UV light of 254, 297, 302, 312 and 365 nm and the survival was measured. Clone-forming ability was chosen as the parameter for cell survival. Melanocytes were found to be less sensitive to UV light than keratinocytes (a difference of a factor 1.22-1.92 for the UV-C and UV-B wavelengths (254, 297, 301 and 312 nm) and a factor 6.71 for the UV-A wavelength (365 nm). Because melanin does not appear to protect against the induction of pyrimidine dimers the difference between melanocytes and keratinocytes in the UV-C and UV-B region could not be explained by the presence of melanin in the melanocytes. The relatively small difference can be explained by the longer cell cycle of melanocytes, which provides more time for the melanocytes to repair UV damage. In the UV-A region the difference between melanocytes and keratinocytes was much larger, suggesting that besides the longer cell cycle some additional factors must be involved in protection against UV-A light.
用254、297、302、312和365纳米的紫外线照射黑素细胞（皮肤2型）和角质形成细胞，并测定其存活率。选择克隆形成能力作为细胞存活的参数。发现黑素细胞对紫外线的敏感性低于角质形成细胞（对于紫外线C和紫外线B波长（254、297、301和312纳米），差异系数为1.22 - 1.92；对于紫外线A波长（365纳米），差异系数为6.71）。由于黑色素似乎不能防止嘧啶二聚体的诱导，因此紫外线C和紫外线B区域中黑素细胞和角质形成细胞之间的差异不能用黑素细胞中黑色素的存在来解释。相对较小的差异可以用黑素细胞较长的细胞周期来解释，这为黑素细胞修复紫外线损伤提供了更多时间。在紫外线A区域，黑素细胞和角质形成细胞之间的差异要大得多，这表明除了较长的细胞周期外，一些其他因素必定参与了对紫外线A的防护。
