硒和锌对细胞氧化低密度脂蛋白作用的影响

Effect of Na_2SeO_3 and ZnSO_4 on Oxidation Modification of Human Low Density Lipoprotein

为探讨微量元素硒和锌在体内抗低密度脂蛋白氧化的作用及其可能机制 ,采用硫代巴比妥酸法测定大鼠动脉平滑肌细胞对低密度脂蛋白的氧化反应 ,采用噻唑蓝法了解动脉平滑肌细胞增殖及邻联二茴香胺底物反应的方法测髓过氧化物酶活性。结果表明 10 μmol/L亚硒酸钠显著减少了丙二醛的生成 ,而相同浓度的硫酸锌效应不明显 ,但二者均可见动脉平滑肌细胞增殖减少。此外 ,低密度脂蛋白诱导动脉平滑肌细胞的髓过氧化物酶活性显著升高 ,但 10 μmol/L亚硒酸钠似乎不能抑制这种效应。提示硒与锌均抑制氧化型低密度脂蛋白促动脉平滑肌细胞的增殖作用 ,前者与抗低密度脂蛋白氧化有关 ,且可能发生在髓过氧化物酶催化形成酪酰基自由基之后的某个环节 ,后者尚待进一步探讨。

Aim The antioxidation effect of Na 2SeO 3 and ZnSO 4, on the oxidation of human low density lipoprotein(LDL) were investigated by rat's arterial smooth muscle cells(ASMC). Methods Oxidation of LDL was induced by rat's ASMC added 1 μmol/L Cu 2+ . The extent of LDL modification was assessed by measuring the formation of thiobarbituric acid reactive substance(TBARS). Results Treatment of 10 μmol/L Na 2SeO 3 and ZnSO 4 inhibited ASMC proliferation by ox-LDL(P<0.01). Treatment of 10 μmol/L Na 2SeO 3 inhibited MDA production(P<0.01), but 10 μmol/L ZnSO 4 have no the effect. 50 mg/L LDL induced myoleperoxidase(MPO) activity, but 10 μmol/L Na 2SeO 3 can not inhitit the effect. Conclusion 10 μmol/L Na 2SeO 3 could protect LDL against rat's ASMC inducing oxidation modification in vitro, which might be contributed by its effect to tyrosyl radical generated by myoleperoxidase.