家兔动脉成形术后血管内膜增殖与普伐他汀联合阿司匹林的干预效应

Interventional effect of Pravastatin combined with Aspirin on inhibiting intimal proliferation in rabbits after percutaneous transluminal angioplasty

目的:观察普伐他汀、阿司匹林联用对家兔颈动脉血管成形术后内膜增殖进展的影响及其作用机制。方法:实验于2002-03/12在北京中医药大学教育部中医内科学重点学科实验室完成。雄性日本大耳白兔30只,体质量1.8～2.0kg,动物适应性喂养1周后随机数字表法分为正常对照组(n=9)、假手术组(n=6)、模型组(n=9)、治疗组(n=6)。模型组和治疗组动物氯胺酮、速眠新混合肌注麻醉,沿气管正中切开皮肤,剥离颈总动脉,给予电刺激。术后第2天开始饲喂高脂饲料(胆固醇:0.7%,猪油:3%,普通饲料96.3%);正常对照组无任何干预措施;假手术组仅剥离颈总动脉,不做电刺激,喂高脂饲料;动物连续喂养8周后超声评价颈总动脉,根据B超选择颈总动脉有斑块或血流明显改变者作颈总动脉球囊扩张术。正常对照组、模型组、假手术组喂普通饲料,治疗组喂普伐他汀与阿司匹林含药饲料(普伐他汀5.046mg/kg,阿司匹林2.268g/kg),4周后测血脂和C-反应蛋白浓度、血清一氧化氮及转化生长因子β水平,观察颈动脉组织病理形态学改变,半定量分析增生内膜中胶原含量的变化,免疫组织化学方法分析增生内膜中巨噬细胞和平滑肌细胞阳性百分率。结果:纳入大耳白兔30只,正常对照组中途死亡1只,死因为牙齿畸型影响进食;模型组1只因电刺激8周时超声评价颈动脉未形成斑块及血流无明显改变而剔出实验,进入分析28只。与模型组比,普伐他汀与阿司匹林联用4周后,治疗组胆固醇及三酰甘油水平明显下降[(4.12±2.30),(0.74±0.17)mmol/L;(0.47±0.27),(0.39±0.14)mmol/L;P<0.05],血清C-反应蛋白水平和转化生长因子β水平均降低[(0.86±0.27),(0.57±0.30)mg/L;(3.45±0.77),(3.23±0.34)ng/L;P<0.05],一氧化氮水平升高[(41.79±35.78),(90.14±32.54)mmol/L;P<0.05],动脉内膜增殖程度明显减轻,管腔狭窄率降低,内中膜厚度及内中膜面积比降低[(71.91±14.90)%,(47.20±18.74)%;(0.41±0.17),(0.26±0.04)mm;1.66±0.63,0.78±0.34;P均<0.05],动脉内膜胶原含量减少(30.92±10.05,21.93±5.81,P<0.01),动脉内膜巨噬细胞阳性百分率降低[(13.94±4.91)%,(7.29±7.28)%,P<0.05],平滑肌细胞含量无明显差异(38.37±5.67,35.79±10.68,P>0.05)。结论:普伐他汀与阿司匹林联用具有抑制内膜增生和减少新生内膜胶原含量的作用,其机制与两药抑制炎症反应、保护内皮功能及抑制细胞外基质生成等有关。

AIM：To observe the effect of Pravastatin combined with Aspirin on intimal proliferation and the mechanism in rabbits after percutaneous transluminal angioplasty （PTA）. METHODS： This article was completed at Key Laboratory of Traditional Chinese Internal Medicine by State Ministry of Education, Beijing University of Chinese Medicine from March to December in 2002. Thirty male Japan flap-eared white rabbits weighing 1.8-2.0 kg were divided randomly into normal control group （n =9）, fake operation group （n =6, feeding with high-fat diet only）, model group （n =9, feeding with high-fat diet and PTA） and Western medicine group （n =6, feeding with medicine）. The atherosclerosis model was created by intramuscular injection of ketamine and sumianxin as well as carotid stimulation with electricity. From the 2^nd day postoperation, the rats were fed with high-fat diet （cholesterol： 0.7%, lard： 3%, common diet： 96.3%）; there was no management in the normal control group; The rats of fake operation group were only fed with high-fat diet without common carotid artery dissection and electricity; all the rats were fed for 8 weeks continuously, the stenosis model in carotid artery ballon-dilatation of rabbit examed with carotid plaque and obvious blood flow by ultrasound were performed an operation of PTA. After operation, the Western medicine group was fed by Pravastatin and Aspirin diet （Pravastatin 5.046 mg/kg, Aspirin 2.268 g/kg）. Four weeks later, blood lipid, C-reactive protein （CRP）, serum nitrogen monoxidum and transforming growth factor （TGF） β were examed; Carotid pathological changes were also observed; intimal collagen were analyzed by half-quantitative analysis method; The positive rate of macrophage and smooth muscle cell in intima were analyzed by immunohistochemical technique. RESULTS： One rat of normal control group died in the experiment due to teeth abnormality affected the food intaking; one rat of model group were deleted owing to the failed model. Thus 28 rats were involved in the result analysis. Four weeks later, the levels of cholesterol and triglyceride were obviously descended in medicine group, compared with the model group [（4.12±2.30）, （0.74±0.17） mmol/L; （0.47±0.27）, （0;39±0.14） mmol/L; P 〈 0.05] and the average levels of CRP and TGF-β were decreased [（0.86±0.27）, ,（0.57±0.30） mg/L; （3.45±0.77）, （3.23±0.34） ng/L; P 〈 0.05], but the level of NO was ascended [（41.79±35.78）, （90.14±32.54） mmol/L; P 〈 0.05]. The combination of Pravastatin and Aspidn could lighten the intimal proliferation, decline the rate of blood vessel stenosis and the ratio of the intimal thickness to area [（71.91±14.90）%, （47.20±18.74）%; （0.41±0.17）, （0.26±0.04） mm; 1.66±0.63, 0.78±0.34; P 〈 0.05], and also descended the content of artery intimal collagen （30.92±10.05, 21.93±5.81, P 〈 0.01） and the positive rate of macrophage [（13.94± 4.91）%, （7.29±7.28）%, P 〈 0.05]. But it had no effect on the content of the smooth muscle cell （38.37±5.67, 35.79± 10.68, P〉 0.05）. CONCLUSION： The combination of Pravastatin and Aspirin can inhibit intimal collagen proliferation and decrease the content of intimal collagen. The mechanism is that, this combination can inhibit the inflammation reaction, protect the endothelia function and inhibit extracellular matrix.