Hengstler J G, Fuchs J, Gebhard S, Oesch F
Institute of Toxicology, University of Mainz, Germany.
Mutat Res. 1994 Jan 16;304(2):229-34. doi: 10.1016/0027-5107(94)90215-1.
After in vitro incubation of human peripheral mononuclear blood cells with glycolaldehyde (a putative metabolite of ethylene oxide) for 2 h at 37 degrees C, a dose-dependent increase in DNA crosslinks was observed in a dose range between 1 and 10 mM using the alkaline filter elution technique. The elution rate of mononuclear blood cells after treatment with ionizing radiation (600 cGy) was reduced more than 5-fold if cells were incubated with 10 mM glycolaldehyde for 2 h. After treatment with proteinase K DNA crosslinks were no longer detected in cells incubated with glycolaldehyde. Therefore the crosslinks produced by glycolaldehyde could clearly be identified as DNA-protein crosslinks. Additionally glycolaldehyde induced DNA single-strand breaks in a dose range between 1 and 10 mM. The elution rate of mononuclear blood cells was increased about 18-fold if cells were incubated with 5 mM glycolaldehyde for 2 h using an elution procedure with proteinase K. In vitro incubation of mononuclear cells with ethylene oxide for 2 h at 37 degrees resulted in a dose-dependent increase in DNA single-strand breaks between 0.5 and 10 mM ethylene oxide. Moreover, a time-dependent increase in DNA single-strand breaks after incubation with 1.5 mM ethylene oxide was observed with an increased number of single-strand breaks already detectable after 15 min and a maximum level which was detected after 2 h of incubation. However, no DNA-DNA or DNA-protein crosslinks could be detected although a wide concentration range and many different incubation times were tested. Therefore DNA crosslinks, for which evidence was found in mononuclear blood cells of humans occupationally exposed to ethylene oxide, are possibly generated by glycolaldehyde, a putative intermediate in the metabolism of ethylene oxide to glycolic acid.
在37℃下，将人外周血单个核细胞与乙醇醛（环氧乙烷的一种假定代谢产物）进行体外孵育2小时后，使用碱性滤膜洗脱技术，在1至10 mM的剂量范围内观察到DNA交联呈剂量依赖性增加。如果细胞与10 mM乙醇醛孵育2小时，那么在接受电离辐射（600 cGy）处理后，单个核细胞的洗脱率降低了5倍多。在用蛋白酶K处理后，在与乙醇醛孵育的细胞中未再检测到DNA交联。因此，由乙醇醛产生的交联可明确鉴定为DNA-蛋白质交联。此外，乙醇醛在1至10 mM的剂量范围内诱导DNA单链断裂。如果使用蛋白酶K洗脱程序，将细胞与5 mM乙醇醛孵育2小时，单个核细胞的洗脱率会增加约18倍。在37℃下将单个核细胞与环氧乙烷体外孵育2小时，在0.5至10 mM环氧乙烷之间导致DNA单链断裂呈剂量依赖性增加。此外，在用1.5 mM环氧乙烷孵育后观察到DNA单链断裂呈时间依赖性增加，在孵育15分钟后就已可检测到单链断裂数量增加，在孵育2小时后检测到最大水平。然而，尽管测试了很宽的浓度范围和许多不同的孵育时间，但未检测到DNA-DNA或DNA-蛋白质交联。因此，在职业接触环氧乙烷的人类单个核血细胞中发现有证据的DNA交联，可能是由乙醇醛产生的，乙醇醛是环氧乙烷代谢为乙醇酸过程中的一种假定中间体。
