摘要
目的探讨叶酸及辛伐他汀对高同型半胱氨酸血症(HHcy)引起的大鼠动脉粥样硬化(AS)治疗效果的差异。方法将36只健康8周龄SD雄性大鼠随机分为健康对照组、高蛋氨酸饮食组、叶酸治疗组和辛伐他汀治疗组。12周后,采用高效液相色谱法检测血浆同型半胱氨酸(Hcy)浓度;采用酶法检测血脂浓度;通过光镜和电镜观察胸主动脉形态学变化;采用免疫组织化学方法检测胸主动脉平滑肌细胞中依赖正常T细胞激活表达和分泌的因子(RANTES)、趋化因子受体-1(CCR-1)蛋白的表达;采用反转录-聚合酶链反应(RT-PCR)方法检测胸主动脉平滑肌细胞RANTES、CCR1 mRNA的表达。结果高蛋氨酸饮食组血浆Hcy浓度明显高于其余3组;叶酸治疗组血浆Hcy浓度明显低于辛伐他汀治疗组(P<0.05)。各组大鼠血浆总胆固醇与甘油三酯浓度差异无统计学意义(P>0.05)。光镜和电镜下可见健康对照组大鼠胸主动脉壁基本结构正常,高蛋氨酸饮食组大鼠胸主动脉呈AS早期改变,治疗组大鼠动脉病变较轻。免疫组织化学结果显示,RANTES和CCR-1蛋白在高蛋氨酸饮食组主动脉平滑肌细胞中表达的平均灰度值显著低于其余3组。且在叶酸治疗组表达的平均灰度显著低于辛伐他汀治疗组(P<0.05)。RT-PCR结果亦表明RANTES和CCR-1 mRNA均在高蛋氨酸饮食组主动脉平滑肌细胞中的表达最高。且在叶酸治疗组的表达均显著高于辛伐他汀治疗组(P<0.05)。结论高蛋氨酸饮食能引起大鼠HHcy形成,促进主动脉平滑肌细胞中RANTES及受体CCR-1的表达,进而诱导AS发生,此过程与血脂无关。辛伐他汀及叶酸均可降低血浆Hcy浓度、抑制动脉壁平滑肌细胞中RANTES及CCR-1的表达,减轻Hcy对动脉壁的损伤,防止AS的发生,但以叶酸降低血浆Hcy的作用更强,辛伐他汀对RANTES和CCR-1表达的抑制作用更明显。
Objective To investigate the comparison between the folic acid and simvastatin treatment effects on the rats with atherosclerosis （AS） induced by hyperhomocysteinemia （HHcy）. Methods Thirty-six healthy 8- week-old SD male rats were randomly divided into normal control group, high methionine diet group, folic acid treatment group and simvastatin treatment group. Twelve weeks later, the plasma homocysteine（Hcy） concentrations were detected by high performance liquid chromatography （HPLC）. The concentrations of plasma lipid were determined with enzyme method. The morphological alterations were detected by optics microscope and transmission electron microscope. The expressions of regulated upon activation normal T expression and secretion （RANTES） and chemoattractant cytokines receptor-1 （CCR-1） proteins in aortic smooth muscle cells were assayed with immunohistochemistry. The expressions of RANTES and CCR-1 mRNA were detected with reverse transcription- polymerase chain reaction （RT-PCR）. Results Hcy concentrations in the plasma of rats fed by high methionine diet were significantly higher than those in the other three groups, and the plasma Hcy concentrations of rats treated with folic acid were dramatically lower than those in the group treated with simvastatin （P〈0.05）. There were no significant differences about plasma total cholesterol and triglyceride concentrations of rats between different groups （P〉0. 05）. The optic microscope and transmission electron microscope showed that the basic structure of thoracic aortic of normal control group was not altered, the thoracic aortas of high methionine diet group were with AS early alterations, and the alterations in the treatment group were lightened. The immunohistochemistry showed the average grey values of RANTES and CCR-1 proteins in the high methionine diet group were significantly lower than those in the other three groups. The average grey values of RANTES and CCR-1 proteins of the folio acid treatment were dramatically lower than those in the simvastatin treatment group （P〈0.05）. RT-PCR showed the expressions of RANTES and CCR-1 mRNA in the high methionine diet group were significantly higher than those in the other three groups. And the expressions of RANTES and CCR-1 mRNA of the folio acid treatment were dramatically higher than those in the simvastatin treatment group （P〈0.05）. Conclusion The high methionine diet can lead to HHcy in rats, increase the expressions of RANTES and CCR-1 in smooth muscle cells of the aorta, and exacerbate atherogenesis, but high methionine diet can not result in higher lipidemia. Both of simvastatin and folic acid can decrease the concentrations of plasma Hey, inhibit RANTES and CCR-1 expressions in arterial smooth muscle cells of rats with HHcy, reduce the injury of aorta walls induced by Hcy, and prevent atherogenesis. The folio acid may play a more important role in reducing the concentration of plasma Hey, and simvastatin much more significantly inhibits the expressions of RANTES and CCR-1.
