Interaction of coronary hemodynamical and biomolecular signals

我们组织了这个跨学科的项目，以提供一个更好的理解层次结构的冠状动脉系统的调节血液动力学和代谢刺激。本研究之主要发现、意涵及未来合作研究方向建议如下：1.借助针探头CCD活体显微镜和冠状动脉灌注系统，我们首次通过控制冠状动脉血流动力学来评价心肌缺血风险最大的内膜下心肌层的微血管行为.不仅心外膜下小动脉，而且心内膜下小动脉的直径也随着冠状动脉灌注压的变化而迅速变化.在体研究冠状动脉内皮源性一氧化氮对切应力变化的即时反应，并探讨一氧化氮在搏动性冠状动脉血流动力学和心肌能量相互调节中的作用.从细胞能量学和分子信号传导的角度提出了新的心肌性能力学能量评价方法。为了将在体心肌能量学与冠脉调节结合起来，建议考虑心脏射血过程中的惯性矩。由于心肌内微循环流量和压力对冠状动脉血流动力学的响应比以往预测的要快，因此有必要进一步提高冠状动脉微循环测量系统的时空分辨率。

We organized this interdisciplinary project in order to provide a better undestanding of the regulation of the hierarchically structured coronary systems to hemodynamical and metabolic stimuli. Followings are the major findings, implicatins, and suggestions for the future direction of the collaborative research on coronary circulation.1. With aids of needle-probe CCD intravital microscopy and coronary perfusion system, we evaluated for the first time the microvascular behavior in the subendocardial myocardial layrs which is at greatest risk of ischemia in the heart by controlling coronary arterial hemodynamics.2. Not only subepicardial but also subendocardial arterioles showed rapid change in diameter in response to a change in coronary perfusion pressure.3. Immediate response of coronary endothelium-derived nitric oxide to a change in shear stress was evaluated in vivo and contribution of nitric oxide to the mutual regulation of pulsatile coronary hemodynamics and myocardial energeticfs was suggested.4. New mechanoenergetic evaluation of the myocardial performance was proposed in relation to the cellular energetics and molecular signaling. To incorporate myocardial energetics with coronary regulation in vivo, it was suggested taht moment of inertia during cardiac ejection should be taken into account.5. Since the responses of intramyocardial microcirculatory flow and pressure to the coronary hemodynamics are quicker than ever predicted, further improvement of the spatiotemporal resolutions of the measuring systems of the coronary microcirculation is necessary.