【摘要】 目的:建立动脉粥样硬化不稳定斑块动物模型,观察黑米花色苷对动脉粥样硬化不稳定斑块及诱导型一氧化氮合酶mRNA表达的影响。方法:实验于2004-06/2006-10在中山大学公共卫生学院营养系完成。黑米花色苷从广东省广州市产的黑优占品种的米皮中提取纯化,主要成分为矢车菊定-3-葡萄糖苷和芍药定-3-葡萄糖苷。48只4周龄脂蛋白E基因敲除C57BL/6J小鼠,平均体质量(21±3)g,抽签随机分为3组:黑米花色苷组、辛伐他汀组和对照组,其中黑米花色苷的添加剂量为1g/kg饲料,辛伐他汀为0.5g/kg饲料,每组16只,雌雄各8只。所有小鼠分笼喂养在层流架中,自由饮水摄食,室温24℃,每两天用紫外灯消毒1次以保持层流架的无菌环境,30周后麻醉颈椎脱臼处死,磷酸盐缓冲液灌注后取出无名动脉,苏木精-伊红染色进行组织学观察,并提取RNA检测诱导型一氧化氮合酶表达变化。结果:48只小鼠均进入统计分析。①脂蛋白E基因敲除小鼠饲喂基础饲料30周在无名动脉处能观察到钙化、薄纤维帽及大脂核等不稳定斑块的典型特征。②与对照组小鼠相比,黑米花色苷组出现具有三层以下细胞组成的薄纤维帽、占斑块面积>50%的大脂核等特征的动脉粥样硬化斑块的频率分别降低了57.38%和53.13%;与对照组小鼠相比,辛伐他汀组薄纤维帽和大脂核出现的频率也分别降低了51.29%和64.25%,而3组间出现钙化现象斑块的频率差异不显著。③黑米花色苷组和辛伐他汀组与对照组相比,诱导型一氧化氮合酶mRNA的表达分别下降了39.26%和45.82%,而黑米花色苷组与辛伐他汀组相比,诱导型一氧化氮合酶mRNA的表达量差异不显著。结论:脂蛋白E基因敲除小鼠可作为动脉粥样硬化不稳定斑块实验动物模型,黑米花色苷能促进斑块稳定性,这种作用与不稳定斑块诱导型一氧化氮合酶表达下调有关。更多还原

【Abstract】 AIM: To establish the animal model of atherosclerotic vulnerable plaque, and further explore the effects of anthocyanin-rich extract from black rice on the atherosclerotic vulnerable plaque and the expression of inducible nitricoxide synthase (iNOS). METHODS: The experiment was conducted in the Department of Nutrition, Public Health School of Sun Yet-sen University between June 2004 and October 2006. The anthocyanin was extracted from black rice (Oryza sativa L.) produced by Guangzhou city in Guangdong Province. Its major contents were cyaniding-3-glucoside and peonidin-3-glucoside. A total of 48 ApoE-knock-out mice with an age of 4 weeks and an average body mass of (21±3) g on a C57BL/6J back ground were randomly divided into three groups: anthocyanin group (1 g/kg diet), simvastatin group (0.5 g/kg diet) and control group with 16 mice half in male and half in female in each group. All mice were fed in rack at 24 ℃ with free access to food and water. The uviol lamp was used every other day for the rack to maintain sterile environment. After 30 weeks, the mice were killed by cervical vertebrae dislocation under anesthesia. The innominate arteries were harvested after perfused with phosphate buffered saline (PBS). Hematoxylin-eosin dyeing was used for histological observation and the mRNA was extracted for detecting iNOS expression. RESULTS: Totally 48 mice were involved in the analysis of results. ①The atherosclerotic vulnerable plaque characteristics such as calcification, thin fibrous cap and large lipid core in ApoE-knock-out mice fed with AIN-93 forage for 30weeks. ② The number of atherosclerotic vulnerable plaques with thin fibrous cap and large lipid core ( > 50%) decreased 57.38% and 53.13% in the anthocyanin group and 51.29% and 64.25% in the simvastatin group compared with those of the control group respectively. But there was no difference in the number of plaques with calcification between the three groups. ③ The iNOS mRNA expression in innominate arteries vulnerable plaque decreased by 39.26% and 45.82% respectively in the anthocyanin group and the simvastatin group compared with those of control group, whereas there was no difference between the anthocyanin group and simvastatin group. CONCLUSION: The ApoE-knock-out mice can be used as the animal models of atherosclerotic vulnerable plaque. The anthocyanin-rich extract from black rice can promote the stability of vulnerable plaque in ApoE-knock-out mice, which may contributes to down-regulate the iNOS mRNA expression.更多还原