CABG术后冠状动脉竞争血流对LIMA血流ET、NO含量的影响

目的:研究冠状动脉分流(CABG)术后冠状动脉竞争血流对左乳房内动脉(LIMA)桥血流中内皮素(ET)、一氧化氮(NO)含量的影响,探讨动脉桥血管早期衰坏的分子机制。方法:建立猪CABG术后桥血管竞争血流动物模型,利用血流闭塞器造成冠状动脉不同程度狭窄,测量桥血管血流量及方向变化,并采用放射免疫分析法及硝酸还原酶法分别检测LIMA桥血流中ET、NO含量并进行对比分析。结果:冠状动脉左前降支(LAD)近端狭窄程度越轻,LIMA桥血流量越少;LAD近端未完全闭塞时,LIMA桥均出现双向血流。CABG术后LIMA桥血流ET含量明显高于移植前(P<0.05),NO含量明显低于移植前(P<0.05)。LAD近端冠脉竞争血流越大,LIMA桥血流NO含量越低。LIMA桥血流NO含量与LIMA桥血流量呈正相关(r=0.957,P<0.05)。LAD近端30%狭窄时,NO含量明显低于LAD近端90%狭窄及全部闭塞时(P<0.05),LAD近端50%狭窄时,NO含量明显低于LAD近端全部闭塞时(P<0.05)。LIMA桥血流ET含量有随LAD近端冠脉竞争血流增加而升高的趋势,但差异无统计学意义(P>0.05)。结论:来自未完全闭塞冠状动脉的竞争血流可引起LIMA桥血流量下降,产生双向血流,并导致桥血流中NO含量显著下降。

Effects of competitive flow from differently stenotic coronary artery on the content of ET and NO in the blood in internal mammary artery graft

Objective: To study the effect of competitive flow from differently stenotic coronary artery on the content of ET and NO in the blood in internal mammary artery graft.Methods: Coronary artery bypass grafting(CABG) was performed in 15 Chinese miniswines using left internal mammary artery(LIMA) anastomosed to left anterior descending artery(LAD).The proximal LAD was mad differently senotic through a flow occluder,and the content of ET and NO in the blood of LIMA graft were respectively measured.Results: The content of ET in the blood in LIMA after grafting was significant higher than that before grafting and the content of NO after grafting was significant lower than that before grafting(P<0.05).The higher the competitive flow of LAD was proximal to the anastomosis,the higher the content of ET and the lower the content of NO was in blood in LIMA graft.The content of NO in blood of LIMA graft was significant lower when the stenosis of the proximal LAD was 30% than that when the stenosis of the proximal LAD was 90% or 100%(P<0.05).The content of NO in blood of LIMA graft was significant lower when the stenosis of the proximal LAD was 50% than that when the stenosis of the proximal LAD was 100%(P<0.05).Conclusion: The competitive flow from nature LAD has important effects on the content of ET and NO in the blood in internal mammary artery graft,and the change of the content may be an important cause of IMA graft earlier failure.