血清和血浆对甲醛诱导性细胞内DPC形成的促进作用

为了探讨胎牛血清和血浆对甲醛诱导性细胞内DNA-蛋白质交联的影响,以昆明纯系小鼠直接分离肝细胞为试验材料进行体外染毒实验,采用KCl-SDS沉淀法检测甲醛染毒后肝细胞中DNA-蛋白质交联含量.结果表明,当缺乏胎牛血清和血浆时,500μmol·mL-1甲醛仅引起较低水平的交联效应,而加入胎牛血清和血浆以后,甲醛诱导的DPC极显著上升(p<0.01).血浆作用比胎牛血清更明显,但二者无显著性差异.结果提示,胎牛血清和血浆对甲醛诱导性DPC形成具有促进作用,而不是以前学者认为的缓冲作用,这可能是甲醛远距离毒性的基础.

Promotion of Fetal Serum and Plasma on Formaldehyde Induced DNA-Protein Crosslink in Cells

In order to explore the effects of fetal serum and plasma on formaldehyde induced DNA-protein crosslink(DPC)in cells,KCl-SDS assay was applied to determine the amount of DPC in liver cells isolated from purebred Kunming mice. Results showed that formaldehyde as 500μmol·mL-1 induced relatively low amount of DPC at the absence of fetal serum and plasma. But DPC formation was significantly elevated in the presence of fetal serum and plasma(p < 0.01). Effects of plasma were somewhat more obvious,however,with no significant difference. These results indicate that fetal serum and plasma have stimulative effects,instead of buffer effects,on formaldehyde induced DPC formation. Such stimulative effects may be important mechanism for the site-distant toxicity of inhaled formaldehyde.