阿托伐他汀对动脉粥样硬化兔脑组织炎性反应的干预作用

Interventions of atorvastatin for inflammatory reaction in brain tissue of atherosclerotic rabbit

目的观察阿托伐他汀对动脉粥样硬化兔脑组织血管紧张素Ⅱ(AngⅡ),核转录因子κB(NF-κB)和诱导型一氧化氮合酶(iNOS)水平的影响,探讨其改善动脉粥样硬化性脑血管病的机制。方法24只新西兰白兔随机分为正常对照组、高脂饮食组及阿托伐他汀组,每组8只兔。正常对照组每日给予普通颗粒兔饲料100g/d,高脂饮食组每日给予普通颗粒兔饲料100g+1.5%胆固醇;阿托伐他汀组每日给予高脂饮食组相同饲料喂养同时给予阿托伐他汀(2.5mg/kg)。喂饲8周后,测定血清总胆固醇及低密度脂蛋白胆固醇的浓度;取颈总动脉行苏丹IV染色,光镜下观察;取海马区脑组织,用免疫组化法检测AngⅡ、NF-κB的表达;Western印迹测定NF-κB的表达;分光光度法测定iNOS的活力。结果以下各项的结果描述按高脂饮食组、阿托伐他汀组、正常对照组顺序①光镜下检查:高脂饮食组可见大量泡沫细胞聚集、炎性细胞浸润;阿托伐他汀组仅有少量泡沫细胞及炎性细胞浸润;正常对照组细胞结构正常。②免疫组织化结果:3组AngⅡ阳性单位分别为17.1±2.7、15.3±1.7、5.2±1.3,NF-κB为22.2±2.6、9.5±1.1、6.9±1.6,与高脂饮食组比较,阿托伐他汀组AngⅡ、NF-κB表达差异均有统计学意义(P<0.01)。③Western印迹:NF-κB吸光度值3组分别为0.9988±0.0041、0.5810±0.0020及0.5621±0.0024,高脂饮食组NF-κB表达较正常对照组及阿托伐他汀组明显升高(P<0.01)。④iNOS的活力:3组iNOS吸光度值分别为10.0±0.9、4.8±0.6、3.4±0.4,阿托伐他汀组较高脂饮食组显著降低(P<0.01),但是仍然高于正常对照组(P<0.01)。结论阿托伐他汀能通过抑制AngⅡ,NF-κB,iNOS的表达减轻高脂血症对脑组织的炎性损伤。

Objective To observe the effect of atorvastatin on the levels of Angiotensin Ⅱ （ Ang Ⅱ ） , Nuclear factor Kappa B （NF-κB） and inducible nitric oxide synthase （iNOS） in brain tissue of atherosclerotic rabbit and to investigate its mechanism of improving atherosclerotic cerebrovascular disease. Methods Twenty-four New Zealand white rabbits were randomly allocated into： a normal control, a high-fat diet and an atorvastatin group, 8 rabbits in each group. The rabbits in the normal control group were fed with common pellet feed 100 g/d, in the high-fat diet group were fed with common pellet feed 100 g ＋ 1.5% cholesterol/d, and in the atorvastatin group were fed the same feed as the high-fat diet group and atorvastatin 2.5 mg/kg/d. After feeding for 8 weeks, the levels of serum total cholesterol （TC） and low density lipoprotein cholesterol （LDL-C） were observed; the expressions of Ang Ⅱ and NF-κB were detected by immunohistochemistry; the expression of NF-κB was detected by Western blot; and the activities of iNOS were measured by spectrophotometry. Results （1）Light microscopic examination of the train tissue in the high-fat diet, atorvastatin and normal control groups： A great deal of foam cells aggregation and inflammatory cells infiltration were observed in the high-fat diet group. There were only a few foam cells and inflammatory cell infiltration in the atorvastatin group. The cell structure was normal in the normal control group. （2）The results of immunohistochemistry： The Ang Ⅱ positive units in the 3 groups were 17.1±2.7, 15.3±1.7 and 5.2 ±1.3 respectively, and the NF-κB were 22.2±2.6, 9.5 ±1.1 and 6. 9 ±1.6, respectively. As compared with high-fat diet group, there were significant differences between the expressions of Ang Ⅱ and NF-KB in the atorvastatin group （P 〈 0. 01 ）. （3）The results of Western blot： The absorbance values of NF-κB in the 3 groups were 0. 9988 ± 0. 0041, 0. 5810 ± 0. 0020 and 0. 5621 ± 0. 0024, respectively. The expression of NF-κB in the high-fat diet group was significantly higher than that of the normal control group and the atorvastatin group （P 〈 0. 01 ）. （4）The activities of iNOS ： The absorbance values in the 3 groups were 10. 0 ±0. 9, 4. 8 ±0. 6 and 3.4 ±0. 4, respectively. Atorvastatin Group was significantly lower than the high-fat diet group （P 〈 0. 01 ）, however, the former was still higher than the normal control group （P 〈 0. 01 ）. Conclusion Atorvastatin may decrease the effect of hyperlipidemia on inflammatory injury of brain tissue by inhibiting the expressions of AngⅡ,NF-κB and iNOS.