CORONARY COLLATERAL FUNCTION

长期目标是描述冠状动脉变化的特征， 侧支功能和阐明机制负责 冠状动脉侧支循环的发展 改善侧支功能，不发生梗死。 研究将 在清醒的小马中进行， 间歇性冠状动脉闭塞刺激侧支循环 功能 将为动物配备多普勒血流仪 左前降支探针和气动封堵器 冠状动脉，测量用超声尺寸量规 心肌节段功能和长期植入导管 左心房前降支和心前静脉 使用本 动物模型允许对心肌血液进行长期观察 血流、代谢和节段功能， 心肌侧支依赖区。 了提问 最佳间歇性冠状动脉闭塞方案， 成熟侧枝的解剖分布， 1）灌注不足区域的大小和形状，2） 心肌去甲肾上腺素释放，3）侧支传导，和 4)开放行为的成熟和功能回归 将检查侧支血管。 局部缺血的作用 与冠状动脉间压力梯度相比， 还将研究刺激抵押的因素。 最后， 冠状静脉血液引流侧支分析 内皮细胞生长因子和其他依赖区 潜在的血管生成因子将在不同的 抵押品发展阶段。 这项工作应该有助于建立 一种有前途的新的冠状动脉和心脏研究动物模型， 并提供关于刺激和行为的原始发现， 对冠状动脉侧支血管成熟的相关认识 和冠心病的治疗。

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.