二氯化汞对人外周血淋巴细胞的遗传毒性及硒的防护作用

环境中的汞对人体健康有潜在危害性。它可与DNA中的不同组分相互作用,引起DNA链断裂和诱发染色体畸变。近来研究表明,硒对汞的毒作用具有防护效应,这对于估价汞的健康损害作用似是一个重要的修饰因子。但是,有关硒对汞化合物引起的DNA

Cytogenetic Toxicity of Mercuric Chloride on Human Lymphoiytes and Preventive Effect of Selenite

The protective effects of sodium selenite (Na₂SeO₃) against the cytogenetic toxicity of mercuric chloride (Hg-Cl₂) were investigated on human whole-blood cultures in relation to induction of sister-chromatid exchanges (SCE) and delay of cell cycle. Mercuric chloride caused a dose-dependent increase in SCE and delay of cell cycle. It strongly affected the ability of human lymphocytes to divide in vitro, the number of cells dividing 3 times within 72 hours in culture was strongly decreased. Sodium se-lenite also induced SCE, but had only a smaller effects at the low concentration (3×10^-6 mol/L) than mercuric chloride, SCE frequency increased significantly in culmre only containing mercuric chloride of 1×10^-5mol/L and cell toxicily appeared in culture only at the concentration of sodium selenite of 1×10^-5 mol/L. Beyond the limits, cell growth stopped. However, when selenite (3×10^-7-1×10^-5 mol/L) was added simultaneously to cell cultures containing mercuric chloride (1×10^-5 mol/L), induction of SCE was prevented and the cell cycle was delayed. The existed a clear doserelated manner. When selenite md mercuric chloride were simultaneously added at a molarratio of Na₂SeO₃:HgCl₂=1:1, cells in treated cultures showed no increase in the SCE frequency and no delay in cell cycle time. These results indicate that selenite and mercury mutually antagonize the ability to cause DNA damage leading to the formation of SCE and the delay of cell cycle.