铬化合物对大鼠不同组织DNA－蛋白质交联物形成的探讨

用铬酸钾对大鼠腹腔注射染毒，以敏感的（１２５）Ｉ－后标记新技术检测不同组织ＤＮＡ－蛋白质交联（ＤＰＣ）的形成情况。结果显示铬酸钾急性染毒后引起白细胞、肝和肾ＤＰＣ明显升高并有剂量反应关系（Ｐ＜０．０５），但无肺ＤＰＣ升高；小量多次染毒结果也与一次染毒相一致。表明ＤＰＣ能反映铬化合物对白细胞和内部器官的遗传毒性，可作为毒作用分子生物标记。结果中还发现白细胞ＤＰＣ的升高比其他组织更明显并与肝ＤＰＣ有相关性（ｒ＝０．９７，Ｐ＜０．０５）。提示白细胞ＤＰＣ可作为某些内部器官的替代物应用于人群生物监测。

Study on Formation of DNA-protein Crosslinks in Different Tissues of Rats Exposed to Chromate Compound

In the present study, we have used a sensitive(125) I-postlabelling assay to detect the formation of DNA-protein crosslinks(DPC)in different tissues from male Sprague-Dawley rats exposed to potassium chromate(K2CrO4). The results demonstrated that 20h after rats were injected i. p. with K2CrO4 ranged from 10 to 40mg/kg, DPC was observed in WBC,liver and kidney in dose-dependent manner,but no DPC.increase was showed in lung. The formation of DPC in different tissues was also observed on rats multiple exposed to the K2CrO4(10mg/kg, i. p, 3w), the results were similar to the single dose. The study showed that the DPC as a biomarker represented quantitatively chromate compound exposure and genotoxic lesions. In addition .DPC was found to be increased more markedly in WBC than in other tissues. There was significant correlation between DPC in WBC and in liver indicating that DPC in WBC may be as a good surrogate for some inner organs to investigation of human population exposed to environmental and occupational agents.