目的

探讨长程增强型体外反搏对高胆固醇血症猪主动脉内皮结构的影响。

方法

18头健康雄性乳猪随机分为正常饲养组、高脂饲养组及高脂饲养+体外反搏组，各6头。后两组同量高脂饲养建立高胆固醇血症猪疾病模型，对高脂饲养+体外反搏组进行36 h的长期体外反搏治疗，取各组动物腹主动脉血管组织，用苏丹Ⅲ染色法观察内膜脂质沉积的改变情况，扫描电镜和透射电镜观察各组动物主动脉内皮结构的变化。

结果

血管内膜苏丹Ⅲ染色结果显示脂纹面积占总内膜面积比例高脂饲养组(9.48%±2.28%)和高脂饲养+体外反搏组(6.53%±0.81%)明显高于正常饲养组(1.66%±0.18%)，P<0.05；且高脂饲养+体外反搏组较高脂饲养组明显减低,P<0.05。提示猪早期动脉粥样硬化疾病模型成功建立，长程体外反搏后主动脉早期动脉粥样硬化的病理改变显著减轻。扫描和透射电镜观察可见正常饲养组血管内皮细胞排列整齐，呈梭状与血流方向一致，大小较均一，表面光滑，内膜完整，内皮与内皮下结构连接紧密，未见平滑肌细胞侵入或增生，无脂质沉积；高脂饲养组血管内皮细胞排列紊乱，内皮细胞有明显脱落，部分细胞胞膜皱缩，体积明显减小，符合凋亡细胞的外形特征，内膜破损明显，平滑肌细胞侵入和增生，脂质沉积，泡沫细胞形成；高脂饲养+体外反搏组血管内皮细胞排列紊乱和大小不一程度介于两组之间，皱缩脱落细胞较高脂饲养组明显减少，可见平滑肌细胞轻度增生和脂质沉积。

结论

高脂饲养组和高脂饲养+体外反搏组主动脉内皮结构改变提示有早期动脉粥样硬化病变形成；长期体外反搏干预可以显著改善高胆固醇血症猪主动脉内皮结构损伤，可能是长期体外反搏发挥抗动脉粥样硬化作用的机制之一。

Objective

To explore the effect of long-term enhanced external counterpulsation(EECP)on morphological damage of endothelium in the aorta of hypercholesterolemic pigs.

Methods

18 male infant pigs were randomly divided into 3 groups according to their diet:the normal control group(n=6),the hypercholesterolemic control group(n=6)and the hypercholesterolemic+EECP group(n=6).Porcine model of hypercholesterolemia was built up by feeding animals with high-cholesterol diet.After completion of EECP treatment for 36 hours on the hypercholesterolemic+EECP group，abdominal aorta were harvested from all animals.Sudan Ⅲfatty streak staining was applied to evaluate macropathological atherosclerotic lesions in aorta endothelium.At the same time,both scanning and transmission electron microscopes were employed to observe the changes of their endothelium in morphology.

Results

Sudan Ⅲstaining in aorta showed that the area percentage of macropathological atherosclerotic lesions was much lower in the hypercholesterolemic + EECP group (6.53%±0.81%)than that in the hypercholesterolemic control group (9.48%±2.28%), but still much higher than that in the normal control group(1.66%±0.18%)，P<0.05；The surface of endothelium in the normal control group was smooth, and endothelial cells arrayed regularly in streamline almost in equal size,attaching closely to matrix without smooth muscle cells proliferation and lipid infiltration in intima.In contrast,the endothelial cells of hypercholesterolemic pigs arrayed irregularly and desquamated markedly,which resulted in looser endothelial linkage;and smooth muscle cells invaded into intimal layer and proliferated, and foam cells could be found in intimal layer. In hypercholesterolemic pigs treated with EECP,slight intimal damage was found.

Conclusion

Long-termEECPimproves the morphological damage resulting from hypercholesterolemia,contributing to postponing atherogenesis and progression of the early atherosclerosis lesions.