缺氧复氧损伤对血管内皮细胞分泌一氧化氮及其合酶活力的影响及辛伐他汀的干预作用

Effects of hopoxia-reoxygenation on secnetion of NO and activity of NOS in vascular endothelial cells and preventive effect of simvastatin

目的:探讨缺氧复氧对血管内皮细胞分泌一氧化氮(NO)及NO合酶(NOS)活力的影响及辛伐他汀的干预作用,并分析其产生作用的可能机制。方法:体外培养人脐静脉内皮细胞株ECV304,使用自制的缺氧小室对ECV304进行缺氧复氧处理。第1实验:仅进行缺氧复氧处理。第2实验:不同浓度的辛伐他汀(0.1、1.0、10.0μmol/L)以及10.0μmol/L辛伐他汀加0.2mmol/L甲羟戊酸预处理ECV30424h后,再行缺氧2h复氧2h处理。硝酸还原酶法及化学比色法分别检测培养液上清中NO的含量及NOS活力。结果:缺氧2h、复氧2、4hECV304分泌NO与对照组相比明显减少,复氧2、4hNOS活力与对照组相比明显下降;经1.0、10.0μmol/L浓度辛伐他汀预处理ECV304后再行缺氧复氧处理则NO含量及NOS活力较对照组明显增加;同时用辛伐他汀和甲羟戊酸预处理后NO含量和NOS较对照组差异无统计学意义。结论:缺氧复氧应激下血管内皮细胞分泌NO功能下降、NOS活力降低;辛伐他汀可以阻止因缺氧复氧刺激导致的NO减少及NOS活力下降,该作用可被甲羟戊酸逆转。

Objective：To investigate variation of oxide （NO） secretion and nitric oxide synthase （NOS） activity in human endothelial cells during hypoxia-reoxygenation, and the effect of simivastatin on them. Methods：ECV304 cells were cultured in vitro and stimulated by hypoxra and reoxygenation, part of which were treated with simvastatin at various concentrations （0. 1, 1.0, 10.0 μmol/L） and 10.0 μmol/L simvastion plus 0.2 mmol/L meoalonate for 24 hours, before they were stimulated by hypoxia and veoxygenation for two hours respectivly. The concentration of NO in the supernatants was determined by nitrate reductase assay, and the activity of NOS was measured by chemical colorimetric assay. Results：The concentration of NO and the activity of NOS in human endothelial cells in hypoxia-reoxygenation group was significantly decreased than that in the control group, and they were increased by pretreatment with simvastatin, but they had no changes compared to the control group, when they were pretreated by simvastatin plus mevalonate. Conclusion：Stress induced by hypoxia-reoxygenation declines the secretion of NO and activity of NOS in vascular endothelial cells simvastatin restores NO secretion and NOS activity in cultured endothelial cells during hypoxia-reoxygenation, and mevalonate reverses this effect.