一卤代甲烷与DNA及血红蛋白结合的研究

Study on Binding of Monohalomethanes to DNA and Hemoglobin

本研究对经口和吸入染毒^(14)C标记一卤代甲烷(一氯甲烷、一溴甲烷及一碘甲烷)的大鼠的血红蛋白(Hb)结合及DNA结合采用液闪放射性计数法进行了测定。三种一卤代甲烷均可与Hb及DNA形成剂量相关性结合,一溴甲烷最强,一碘甲烷次之,一氯甲烷最弱。Hb结合与DNA结合之间未显示明显的相关关系,但与DNA结合能力强的一卤代甲烷,与Hb的结合能力亦强。以上结果提示Hb结合可代替DNA结合而用于这类物质的生物学监测。

Covalent binding to hemoglobin (Hb) and DNA of monohalome-thanes(methyl chloride,methyl bromide,methyl iodide) in orally and inhalati-vely exposed F-344 rats was determined by counting Hb and DNA bound radioactivity.All the three chemicals showed dose-dependent binding to Hb and DNA.Although no clear correlation between Hb and DNA binding could be observed,the results indicated that chemical (methyl bromide) with the highest efficiency to methylate DNA was the most reactive for binding to Hb.It was ' also shown that different modes of administration influenced the amount of Hb binding,prabably by affecting the local concentrations of the chemicals.Hb binding as a parameter for biomonitoring the exposure to these chemicals was also discussed