体外反搏对动脉粥样硬化猪血管舒张功能的影响

Effects of long-term enhanced external counterpulsafion on endothelimn-dependent and endothelium-independent vasorelaxafion of the carotid arteries in atherosclerofic pigs

目的探讨长期体外反搏对动脉粥样硬化猪内皮依赖和非内皮依赖血管舒张功能的影响。方法猪龄20d雄性乳猪18头随机分为正常饲养组（n=6）、高脂饲养组（n=6）及高脂饲养＋体外反搏组（n=6）。后两组通过高脂饲养复制动脉粥样硬化猪疾病模型，对高脂饲养＋体外反搏组进行为时36h的长期体外反搏治疗，取各组动物颈动脉血管环，测定离体颈动脉血管环对不同浓度梯度乙酰胆碱和硝普钠的舒张反应，用单因素方差分析法比较三组动物血管舒张率的差异。结果在乙酰胆碱10^-8～10^-5mol／L浓度范围内，高脂饲养组和高脂饲养＋体外反搏组的血管舒张率较正常饲养组显著降低（P〈0．05）；在10^-7～10^-5mol／L浓度范围内，高脂饲养＋体外反搏组的血管舒张率较高脂饲养组明显提高（P〈0．05）。在硝普钠10^-8～10^-5mol／L浓度范围内，高脂饲养组和高脂饲养＋体外反搏组的血管舒张率较正常饲养组显著降低（P〈0．05）；在10^-8～10^-5mol／L浓度范围内，高脂饲养＋体外反搏组的血管舒张率较高脂饲养组明显提高（P〈0．05）。结论高脂饲养组和高脂饲养＋体外反搏组内皮依赖血管舒张功能和非内皮依赖血管舒张功能较正常饲养组明显受损，长期体外反搏干预可以显著改善动脉粥样硬化猪内皮依赖和非内皮依赖血管舒张功能，这可能是长期体外反搏具有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 endothelium-dependent and endothelium-independent vasorelaxation in the carotid arteries of atherosclerotic pigs. Method Totally 18 20-day-old male infant pigs were randomly divided into 3 groups according to feeding given： the normal control group （ n = 6）, the hypereholesterolemic control group （ n = 6） and the hypereholesterolemic ＋ EECP group （ n = 6）. Porcine model of hypereholesterolemia was made by feeding high-cholesterol diet. After EECP for 36 hours in the hypereholesterolemic ＋ EECP group（ n = 6）, carotid arterial rings were harvested from all animals and their vaso-relaxation response to different dose of Acetylcholine（Ach） and Sodium nitroprusside （SNP）were detected, respectively. Results As the dose of Ach varying between 10^-8 mol/L and 10^-5 mol/L, endothehum-dependent vasorelaxation ratio of hypereholesterolemic pigs with or without EECP treatment was significantly lower than that of the normal control group （ P 〈 0.05）, however,endothelium-dependent vasorelaxation ratio in pigs with EECP treatment was obviously higher compared with hypereholesterolemic pigs without EECP treatment （ P 〈 0.05） as the Ach ranged from 10^-7 mol/L to 10^-5 mol/L. Similarly,as the concentration of SNP ranged from 10^-8 mol/L to 10^-5 mol/L, endothehum-independent vasorelaxation ratio of both the hypercholesterolemic control group and the hypercholesterolemic ＋ EECP group were significantly lower than that of the normal control group （ P 〈 0. 05 ）, and endothelium-independent vasorelaxation ratio of the hypercholesterolemic ＋ EECP group was significantly higher than that of the hypercholesterolemic control group （ P 〈 0.05）. Conclusions long-term EECP improves the impaired endothelitun-dependent and endothelium-independent vasorelaxation function resulting from atheroselerosis.