硒对大鼠肝细胞增殖周期和DNA合成的影响
Effects of selenium on rat's hepatocellular DNA synthesis and cell cycle changes
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摘要:目的 研究亚硒酸钠对大鼠肝细胞增殖周期和DNA合成的影响.方法 选用雄性SD大鼠, 每组5只, 用5, 10和20μmol/kg的亚硒酸钠腹腔注射染毒.用流式细胞术研究大鼠肝细胞增殖周期和DNA相对含量(DNARC), 用单细胞凝胶电泳检测DNA损伤.结果 .10和20μmol/kg的亚硒酸钠均可使大鼠肝细胞G0/G1期细胞显着减少, 5μmol/kg的亚硒酸钠虽可使G0/G1期细胞减少, 但无显着性差异.S期和G2/M期细胞以及增殖指数变化不明显.5, 10和20μmol/kg的亚硒酸钠可引起大鼠肝细胞DNARC下降, DNA损伤率较对照组显着增高, 而且DNARC和DNA损伤率之间存在负相关关系, 随DNA损伤率的增高, DNARC下降, 相关系数为: -0.9887(P < 0.01).结论 一定剂量的亚硒酸钠不仅改变了大鼠肝细胞的增殖周期, 还引起DNA损伤, 并影响DNA合成, 使DNA相对含量显着下降.Abstract:Objective To explore effects of selenium on rat's hepatocellular DNA synthesis and cell cycle changes.Methods So dium selenite at the dose of 5, 10 and 20 μmol/kg were given to rats by i.p.and there were 5 male SD rats in each group.Hepato cellular DNA damage was measured with single cell gel electrophoresis(or comet assay), DNA relatiev content (DNARC)and cell cycle were detected with flow cytometry.Results At the dose of 10 and 20 μmol/kg, sodium selenite could reduce cell number of G0/G1 period, but significantly.At the dose of 5μmol/kg, sodium selenite could also reduce cell number of G0/G1 per iod, but insignificantly.The changes of proliferation index and cell number in S and G2/M period were unobvious.Sodium selenite at the dose of 5, 10μmol/kg and 20μmol/kg could increase DNA damage rate and decerease DNARC significantly.There was negative correlation between DNA damage rate and DNA relative content.Correlative coefficient was -0.998 7(P < 0.01).Conclusion Selenium at certain dose could change cell cycle and interfere with DNA synthesis throug h increasing DNA damage rate and decreasing DNA relative content in rat liver cells.
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