Qin X, Zhang S, Zarkovic M, Nakatsuru Y, Shimizu S, Yamazaki Y, Oda H, Nikaido O, Ishikawa T
Department of Pathology, Faculty of Medicine, University of Tokyo.
Jpn J Cancer Res. 1996 Jul;87(7):685-90. doi: 10.1111/j.1349-7006.1996.tb00278.x.
In the present study, we for the first time investigated the formation of ultraviolet (UV) photoproducts, cyclobutane pyrimidine dimers (CPDs), pyrimidine-pyrimidone (6-4) photoproducts (64PPs) and Dewar isomers, in vivo in shaved and depilated C3H/HeN mouse skin exposed to natural sunlight (NSL) at noon for 5 min to 1 h in mid-summer, using a highly sensitive immunohistochemical method. This method permits the quantitative analysis of UV-photoproducts in formalin-fixed, paraffinembedded sections with specific antibodies against CPDs, 64PPs and Dewar isomers. We demonstrated that the induction of CPDs in vivo in mouse skin by NSL was exposure time-dependent, but the accumulation of 64PPs or Dewar isomers was comparatively low in the skin sections from mice exposed to NSL in vivo. The results indicate that CPDs are the main photoproducts in vivo induced by sunlight and that their formation and repair may be important in connection with carcinogenesis in sun-exposed areas of human skin.
在本研究中，我们首次使用高度灵敏的免疫组织化学方法，调查了在仲夏中午将剃毛和脱毛的C3H/HeN小鼠皮肤暴露于自然阳光（NSL）下5分钟至1小时后，体内紫外线（UV）光产物、环丁烷嘧啶二聚体（CPD）、嘧啶 - 嘧啶酮（6 - 4）光产物（64PP）和杜瓦异构体的形成情况。该方法允许使用针对CPD、64PP和杜瓦异构体的特异性抗体，对福尔马林固定、石蜡包埋切片中的UV光产物进行定量分析。我们证明，NSL在小鼠皮肤中体内诱导CPD是暴露时间依赖性的，但在体内暴露于NSL的小鼠皮肤切片中，64PP或杜瓦异构体的积累相对较低。结果表明，CPD是阳光在体内诱导产生的主要光产物，并且它们的形成和修复可能与人类皮肤暴露于阳光下区域的致癌作用有关。
