EFFECTS OF ISCHEMIA ON THE CORONARY MICROCIRCULATION

我们研究冠状动脉的能力的最新技术进展 微循环在体内和体外都开辟了一个新的前景， 与冠状动脉微循环调节相关的研究。 我们实验室的观察表明，大约一半的冠状动脉 血管阻力存在于大于100 μ m的动脉血管中， 大小和冠状动脉微血管阻力的分布是 在冠状动脉闭塞或严重的 冠状动脉阻塞 拟议研究的目的是 开展进一步调查，以了解 在控制条件下调节冠状动脉循环， 在心肌缺血期间。 主要次级目标涉及： 外源施加和内源释放的物质（血栓烷， PGI 2、白三烯、去甲肾上腺素、腺苷和5-羟色胺）对 冠状动脉微血管阻力的分布;区域性研究 冠状动脉微循环通透性的改变 再灌注;受体在不同大小动脉中的分布 微血管;以及，硝酸甘油和硝苯地平对微血管的影响。 冠状动脉微血管阻力分布。 这些调查的完成将大大增加我们的基本 了解在心肌缺血状态下调节心肌灌注的机制 对照条件和各种心肌缺血模型。

Recent technological advances in our ability to study the coronary microcirculation both in vivo and in vitro have opened a new vista of research related to regulation of the coronary microcirculation. Observations from our laboratory indicate that about one-half of coronary vascular resistance exists in arterial vessels larger than 100 mu m in size and that the distribution of coronary microvascular resistance is dramatically altered in the presence of coronary occlusion or a severe coronary obstruction. The purpose of the proposed studies will be to perform further investigations aimed at understanding mechanisms that regulate the coronary circulation both under control conditions and during myocardial ischemia. Major subaims are related to: effects of exogenously applied and endogenously released substances (thromboxane, PGI2, leukotrienes, norepinephrine, adenosine and serotonin) on the distribution of coronary microvascular resistance; studies of regional alterations in permeability in the coronary microcirculation following reperfusion; distribution of receptors in various class sizes of arterial microvessels; and, effects of nitroglycerine and nifedipine on the distribution of coronary microvascular resistance. Completion of these investigations should significantly augment our basic understanding of mechanisms that regulate myocardial perfusion under control conditions and in various models of myocardial ischemia.