CORONARY COLLATERAL FUNCTION

长期目标是确定冠状动脉病变的特征。 络脉功能和解释机制负责 进行性冠状动脉侧支循环发育的研究 改善侧支功能，无梗死。研究将会是 在意识清醒的小马中表演，并接受 间歇性冠状动脉闭塞刺激侧支循环 功能。这只动物将用多普勒血流进行测量。 左前降支探头及气囊封堵器 冠状动脉，测量用超声波内径测量器 心肌节段功能与长期植入的导管 在左心房、左前降支和心脏前静脉。使用这个 动物模型允许对心肌血进行长期观察 反复缺血的血流、代谢和节段功能， 心肌侧支依赖区。关于以下问题： 最佳的间歇性冠状动脉闭塞方案 成熟络脉的解剖分布及其进展 1)欠灌注区的大小和形状的变化，2) 心肌去甲肾上腺素释放，3)侧支传导，以及 4)成熟和功能回归的开放行为 将检查抵押品血管。区域性脑缺血的作用 与冠状动脉间压力梯度作为主要的 抵押贷款的刺激因素也将被调查。最后， 冠状静脉血引流侧支分析 内皮细胞生长因子和其他依赖区域 潜在的血管生成因子将在不同的 抵押品开发的各个阶段。这项工作应该有助于建立 一种有前途的冠状动脉和心脏研究的新动物模型， 并提供关于刺激和行为的原创性发现 对成熟冠脉侧支相关血管的认识 和治疗冠心病。

The long term objectives are to characterize changes in coronary collateral function and elucidate mechanisms responsible for coronary collateral development under conditions of progressively improving collateral function without infarction. Studies will be performed in the conscious pony subjected to a regimen of intermittent coronary artery occlusions to stimulate collateral function. The animal will be instrumented with a Doppler flow probe and pneumatic occluder on the left anterior descending coronary artery, ultrasonic dimension gauges for measuring myocardial segment function, and chronically implanted catheters in the left atrium, LAD, and anterior cardiac vein. Use of this animal model permits long term observations on myocardial blood flow, metabolism, and segment function in a repeatedly ischemic, collateral dependent region of myocardium. Questions concerning the optimal intermittent coronary occlusion regimen, the anatomical distribution of mature collaterals, and the progression of changes in 1) the size and shape of the underperfused region, 2) myocardial norepinephrine release, 3) collateral conductance, and 4) the opening behavior of maturing and functionally regressed collateral vessels will be examined. The role of regional ischemia versus the inter-coronary artery pressure gradient as the primary stimulus for collateralization will also be investigated. Finally, an analysis of coronary venous blood draining the collateral dependent region for endothelial cell growth factors and other potential angiogenesis factors will be performed at different stages of collateral development. This work should help establish a promising new animal model for coronary and cardiac research, and provide original findings on the stimulus and behavior of maturing coronary collateral vessels relevant to the understanding and treatment of coronary heart disease.