Hamilton J W, Wetterhahn K E
Carcinogenesis. 1986 Dec;7(12):2085-8. doi: 10.1093/carcin/7.12.2085.
Uptake of chromium (VI) and subsequent induction of DNA damage was examined in liver and blood cells of 14-day chick embryos after injection of sodium dichromate onto the inner shell membrane. Maximal loss of chromium from the inner shell membrane and distribution of chromium in liver, lung and blood was observed 2 h after injection. DNA strand breaks, interstrand cross-links and DNA--protein cross-links were measured using the alkaline elution technique. In chick embryo liver, chromium (VI) induced DNA cross-links in the absence of strand breaks. Maximal DNA cross-linking was detected in the liver 8 h after injection. Little or no DNA damage remained in the liver 10-24 h after injection. In contrast, chromium (VI) induced DNA strand breaks in the absence of cross-links in chick embryo blood cells. Maximal DNA strand breakage was observed in blood cells 8 h after injection. High levels of DNA strand breaks were present in blood cells even 24 h after treatment. These intra-embryonic tissue differences in chromium (VI)-induced DNA damage may be a result of the differences in glutathione, cytochrome P-450, other pathways of chromium (VI) metabolism or chromatin organization which exist in liver and blood cells.
将重铬酸钠注射到14日龄鸡胚的内壳膜上后，检测了鸡胚肝脏和血细胞中铬（VI）的摄取及随后DNA损伤的诱导情况。注射后2小时观察到内壳膜中铬的最大损失以及铬在肝脏、肺和血液中的分布。使用碱性洗脱技术测量DNA链断裂、链间交联和DNA-蛋白质交联。在鸡胚肝脏中，铬（VI）在没有链断裂的情况下诱导DNA交联。注射后8小时在肝脏中检测到最大程度的DNA交联。注射后10 - 24小时肝脏中几乎没有或没有DNA损伤残留。相比之下，铬（VI）在鸡胚血细胞中在没有交联的情况下诱导DNA链断裂。注射后8小时在血细胞中观察到最大程度的DNA链断裂。即使在处理后24小时，血细胞中仍存在高水平的DNA链断裂。胚胎内组织在铬（VI）诱导的DNA损伤方面的这些差异可能是由于肝脏和血细胞中谷胱甘肽、细胞色素P - 450、铬（VI）代谢的其他途径或染色质组织存在差异所致。
