等长收缩训练促进犬慢性缺血心肌血流灌注的研究

关键词：等长收缩  心肌缺血  心肌血流灌注  核素灌注显像  毛细血管密度

Keywords:isometric exercise  myocardial ischemia  myocardial perfusion  SPECT  capillary density

摘要：

      摘要 目的：观察主动等长收缩训练对犬慢性缺血心肌血流灌注的影响。 方法：应用Ameroid缩窄器制备犬慢性冠状动脉狭窄模型，造模成功后，将模型动物随机分为2组：对照组（CG组）（n=6），主动等长收缩训练组（AIE组）（n=6）。主动等长收缩训练：采用100%最大强度训练1min，休息1min，每日重复20次，每周训练5天，训练时程为6周。训练6周末，所有模型犬行心脏SPECT成像测定心肌缺血区域血流灌注，免疫组化法测定犬缺血心肌组织毛细血管密度。 结果：AIE组缺血区域静息血流灌注心肌节段总评分（23.00±2.35）较CG组（46.4±8.88）明显降低（P＜0.05），AIE组缺血心肌部位的毛细血管密度（22.40±2.07）显著高于CG组（15.20±5.40）（P＜0.05）。 结论：主动等长收缩训练可以增加慢性心肌缺血犬的心肌毛细血管密度，促进缺血心肌的血流灌注。

Abstract:

      Abstract Objective: To investigate the effects of active isometric exercise training on capillary density and myocardial perfusion in canine model of chronic ischemic myocardium. Method: An Ameroid constrictor was placed around the left anterior descending branch of the left coronary artery in 12 canine. SPECT (single-photonemission computed tomography) imaging was used to evaluate myocardial perfusion. The animals were divided into active isometric exercise training group (AIE) (n=6) and control group (CG) (n=6). Canine in the AIE group performed active isometric exercises for 6 weeks, whereas canine in the CG group remained sedentary. The expression of capillary density was measured by immunohistochemical analysis. Myocardial perfusion was assessed by SPECT imaging. Result: The capillary density in the AIE training group（23.00±2.35）was significantly higher than that in the CG group（46.4±8.88） (P＜0.05). SPECT imaging showed that myocardial perfusion（22.40±2.07） was significantly improved in the AIE training group（15.20±5.40） (P＜0.05). Conclusion: Active isometric exercise could increase the capillary density in the canine model of chronic myocardial ischemia, and thus effectively increase the blood perfusion in ischemic myocardium.