烟酸对动脉粥样硬化大鼠血管内皮功能影响的初步研究

目的了解烟酸对动脉粥样硬化大鼠血管内皮功能的影响，探讨烟酸防治动脉粥样硬化（AS）的作用机制。方法AS模型大鼠分为5组：烟酸高、中、低三个剂量组（15／150／1500mg·kg^-1·d^-1）、AS模型组（高脂饲料）、阳性药物对照组（阿托伐他汀5mg·kg^-1·d^-1），饲养6周，另设正常对照组（正常饮食）。满6周后检测大鼠血液中一氧化氮（NO）、一氧化氮合酶（NOS）、内皮素-1（ET-1）及纤溶酶抑制物-1（PAI—1）水平，观察腹主动脉粥样斑块面积和内膜增殖情况。结果与AS模型组大鼠比较，烟酸处理可使AS大鼠血液中NOS活性增加，NO升高，ET、PAI-1降低，其作用与阿托伐他汀效果没有差异；高、低剂量烟酸使AS大鼠血液NO浓度的增加及ET、PAI-1降低的作用具有统计学意义的差异。与AS模型组大鼠比较，烟酸处理组AS大鼠的内膜增殖比率下降，炯酸的作用存在剂量依赖性；高剂量烟酸处理组AS大鼠内膜增殖的比率与阳性药物组比较没有显著差异。结论烟酸可以改善血管内皮功能，发挥抗AS作用。

Effect of niacin on vascular endothelial cells in rats with atherosclerosis

Objective To explore the effect of niacin on vascular endothelial cells in rats with atherosclerosis (AS) and the mechanism of action of niacin for AS. Methods Rats with AS were divided into5 groups: groups with niacin at high (1500 mg/kg-1/d-1), medium (150 mg), and low dose (15 mg), group with high-fat diets, group with atorvastatin (5 mg/kg-1/d-1). Rats in the blank control group received normal diets.6 weeks after treatment, blood levels of NO, NOS, ET-1, and PAI-1 were detected in all the rats. The area of fibrous plaques and the media proliferation of the abdominal aorta were observed. Results In 3 niacin groups, NOS activity and NO level increased while levels of ET and PAI-1 decreased, and there was no significant difference between the three groups (P>0.05). The rate of media proliferation of the abdominal aorta decreased in niacin groups in a dose-dependent manner and it did not differ significantly between high-dose niacin group and atorvastatin group (P>0.05). Conclusions Niacin can improve the function of vascular endothelial cells and play a role in resisting atherosclerosis progress.