经导管急性冠状动脉内微血管栓塞对微血管完整性及心肌内皮素-1的影响

Effect of acute coronary microembolization on microvascular injury and myocardial endothelin-1 levels

目的:通过经导管建立的急性微血管栓塞的动物模型,研究不同微栓塞水平对微血管完整性及心肌内皮素-1(ET-1)的影响。方法:10头小型猪经导管于前降支(LAD)内多次注入微栓塞球(45μm),致使微血管栓塞。在微栓塞前,以及注入5万、10万、12万、14万和15万微球量时:①放射免疫法测定冠状静脉窦内ET-1的变化以评价心肌ET-1的代谢;②冠状动脉内注射腺苷18μg达到最大充血状态,多普勒导丝测量LAD内血流储备(CFR)以评价微血管的完整性。结果:不同微栓塞水平同微栓塞前相比,CFR均有显著性降低;ET-1呈“双期”改变:5万微球量时显著性增加,10万剂量时到达分泌峰值,随后略有降低并持续至15万微球剂量。CFR同ET-1呈负性相关(r=-0.31,P=0.02)。结论:微血管完整性破坏的程度和心肌ET-1的变化密切相关,但两者同冠状动脉微栓塞的程度均不成正比。

Objective： To investigate the effect of coronary microemboliation （CME） on coronary microvascular injury and myocardial endothelin-1 （ET-1） level. Methods： CME was induced in 10 miniswines by selective infusion of microspheres （45 μm） into left anterior descending artery （LAD）. The ET-1 level in coronary sinus was measured with radioimmunioassay. The microvascular integrity indicator CFR was measured by Doppler flow wire in LAD at baseline and after infusion of microspheres. Results： Compared to the baseline, CFR decreased significantly with different doses of microspheres, ET-1 level increased significantly with doses of 5 × 10^4nd peaked with 10 × 10^4,and progressively decreased from doses of 12 × 10^4 to 15 × 10^4 microspheres. There was negative correlation between ET-1 and CFR （r=-0, 31,P=0.02）. Conclusion： The extent of microvascular injury is not linearly related to the extent of microembolization,but it is closely associated with myocardial ET-1 level.