EFFECTS OF EXERCISE ON THE CORONARY VASCULATURE

为了确定冠状动脉侧支形成的时间过程， 将用铊扫描连续研究冠状动脉闭塞的狗。 闭塞后，将在2天后使用同位素进行首次扫描 在跑步机上跑步时注射。 注射后，动物将 麻醉，以允许扫描超过4小时的时间， 期可以观察到。 然后每5-7天重复扫描一次， 减少缺血面积。 采用犬LAD闭塞和LCF狭窄模型，血流动力学，远端 冠状动脉内给药后，将检查LCF压力和心肌血流量。 硝苯地平注射液。 通过评价药物对远端LCF的影响， 压力和心肌流量，将确定盗血的存在。

To determine the time course of coronary collateral development, instrumented dogs with coronary occlusions will be studied serially with thallium scanning. Following occlusion, the first scan is to be performed 2 days later with isotope injection during treadmill running. Following injection the animals will be anesthetized to permit scanning over a 4-hour period so that the reperfusion period can be observed. Then scans will be repeated every 5-7 days to measure the reduction in area of ischemia. Using the canine model of LAD occlusion and LCf stenosis, hemodynamics, distal LCf pressure, and myocardial blood flow will be examined following intracoronary Nifedipine injection. By evaluating the effect of the drug on distal LCf pressure and myocardial flow, the presence of steal will be determined.