氧化型低密度脂蛋白对血小板一氧化氮合成酶的抑制作用及卡托普利的上调作用

Inhibition of nitric oxide synthase in human platelets by oxidized low density lipoprotein and upregulation by captopril in vitro

目的 研究氧化型低密度脂蛋白 ( ox-L DL)对血小板一氧化氮合成酶 ( NOS)的抑制作用及卡托普利的抗氧化作用及对 NOS活性的上调作用。方法 测定 5 0例动脉粥样硬化患者和 3 0例健康老年体检者血小板悬液 NOS及加入 ox-LDL、卡托普利后 NOS活性的变化。结果 动脉粥样硬化组血小板 NOS活性明显低于对照组 ( P<0 .0 5 ) ;动脉粥样硬化组和对照组血小板加入 ox-LDL 后 NOS活性均显著降低 ( P<0 .0 1) ;两组血小板同时加入ox-LDL 和卡托普利后 NOS活性均明显升高 ( P<0 .0 1) ;两组血小板单纯加卡托普利后 NOS活性均明显升高 ( P<0 .0 1)。血小板 NOS活性变化与 ox-L DL呈负相关 ( r=-0 .989,P<0 .0 1) ,与卡托普利呈正相关 ( r=0 .987,P<0 .0 1)。结论 ox-LDL能抑制血小板 NOS活性 ,而卡托普利不仅有抗氧化作用 ,还能直接上调

Objective To investigate the inhibition of nitric oxide synthase(NOS) activity in human platelets by oxidized low density lipoprotein(ox LDL) and the antioxidant effect, the upregulation directly by captopril in vitro. Metheds The platelets cytosol of the 50 patients with atherosclerosis and the 30 healthy controls were added with ox LDL and captopril followed incubation at 37℃ for 1 hour, then determined the platelet NOS activities. Results The platelet NOS activities of the patients were significantly lower than those of the contros( P <0.05); After incubation with ox LDL, the platelet NOS activities of the patients and controls were all declined significantly compared with before( P <0.01); After incubation with ox LDL and captopril, the platelet NOS activities in the patients and the controls were all increased significantly( P <0.01); After incubation with captopril, the platelet NOS activities in the patients and the controls were all significantly increased( P <0.01). The change of platelet NOS activity was realated to the concentration of ox LDL negatively( r =-0.989, P <0.01) and to the level of captopril positively( r = 0.987 , P <0.01). Conclusion ox LDL can inhibit the platelet NOS activity, captopril not only has antioxidant effect, but also has upregulation of platelet NOS activity directly.