氧化低密度脂蛋白及卡托普利对血小板一氧化氮合酶的作用

目的　研究氧化低密度脂蛋白 (oxLDL)对血小板一氧化氮合酶 (NOS)的抑制作用及卡托普利的抗氧化和对NOS活性的直接上调作用。方法　测定 50例急性脑梗死患者及 30例健康体检者的血小板NOS及在体外加氧化低密度脂蛋白、卡托普利后血小板NOS活性的变化。结果　 ( 1)脑梗死组和对照组血小板加oxLDL后 ,NOS值均明显下降 (P<0 0 1) ,梗死组下降更明显 ;( 2 )两组血小板加卡托普利后 ,其NOS值均明显升高 (P <0 0 1) ,梗死组升高更明显 ;( 3)两组血小板同时加卡托普利、oxLDL后 ,NOS值均明显升高 (P <0 0 1) ,同样梗死组升高更明显。结论　oxLDL能抑制血小板NOS活性 ,而卡托普利不仅有抗氧化作用 ,还能直接上调血小板NOS活性的作用 ,此现象在脑梗死中表现尤为明显。因此 ,卡托普利在脑梗死的防治中可能有重要价值

Effect of Oxidized LDL and Captopril on Platelet Nitric Oxide Synthase

Objective To investigate the inhibition o f platelet nitric oxide synthase (NOS) by oxidized LDL (oxLDL) and the up-regula tion effect of NOS by captopril in vitro.Methods Platel et NOS activity of 50 patients with acute cerebral infarction (patient group) an d 30 healthy people (control group) was measured in vitro after adding oxLDL and captopril to washed platelet.Results (1)After adding o xLDL to the washed platelet in vitro the platelet NOS activities of both patient and control groups were all significantly decreased ( P <0 01).And the plat elet NOS activity of patient group decreased more than that of control group.(2) After adding captopril to the washed platelet in vitro the platelet NOS activiti es of both patient and control groups were all significantly increased ( P <0 01).And the platelet NOS activities of patient group increased more than that of the control group.(3)After adding both captopril and oxLDL to the washed plat elet in vitro at the same time,the platelet NOS activities of both patient and c ontrol groups were all significantly increased ( P <0 01).And the platelet N OS activity of patient group increased more than that of the control group.Conclusions oxLDL inhibits platelet NOS activity,captopril not only has antioxidant effect,but also has upregulation of platelet NOS acti vity directly.And it is more obvious for patient group.Therefore,captopril may p ossess an important role in treatment of cerebral infarction.