摘要
目的 在体外研究六价铬化合物诱导质粒DNA 链断裂的作用。方法 采用质粒松弛法。结果 重铬酸钾(0 .5 mmol/L) 、抗坏血酸(1 mmol/L) 、谷胱甘肽(5 mmol/L) 或过氧化氢(17mmol/L) 单独作用都不能诱导明显的DNA 单链断裂。然而,将重铬酸钾和具有氧化还原功能的物质与DNA 共同温浴,发现重铬酸钾和抗坏血酸、谷胱甘肽或过氧化氢反应后可明显诱导质粒DNA 单链断裂。重铬酸钾和过氧化氢(17 mmol/L) 还诱导质粒DNA 双链断裂。结论 抗坏血酸、谷胱甘肽和过氧化氢可能在重铬酸钾的致癌过程中起重要作用。
Objective To study plasmid DNA breakage induced by hexavalent chromium (Cr Ⅵ+ ) compound in vitro. Methods DNA breakage was observed using plasmid relaxation method. Results pUC 118 plasmid DNA single strand breakage can not be caused by either ascorbic acid (1 mmol/L), or glutathione (5 mmol/L), or hydrogen peroxide (H 2O 2, 17 mmol/L) or potassium dichromate (K 2Cr 2O 7, 0.5 mmol/L) alone. But, if DNA was incubated warmly with K 2Cr 2O 7 and intracellular redox compound, pUC118 plasmid DNA single strand breakage could be induced by K 2Cr 2O 7, ascorbic acid, or glutathione, or products of peroxidation reaction. K 2Cr 2O 7 (0.5 mmol/L) and H 2O 2 (17 mmol/L) also could cause some double strand breakage in plasmid. Conclusion It suggests that ascorbic acid, glutathione and H 2O 2 can play an important role in carcinogenicity of K 2Cr 2O 7.
出处
《中华预防医学杂志》
CAS
CSCD
北大核心
1999年第6期354-356,共3页
Chinese Journal of Preventive Medicine