Analysis on myocardial ischemia by observation of NADH fluorescence/oxygen partial pressure phosphorescence using an intra-vital needle microscope

我们对心肌缺血最常见的心脏内膜微循环的代谢功能和氧分压图像进行了体内分析。本研究的目的是阐明冠状动脉微循环的病理生理。我们做到了；1)针透镜的研制2)NADH激动器及其荧光观测器的研制（激发波长370 nm，荧光460 mm）3) pd -卟啉激动器及其荧光观测器的研制（激发波长545 nm，荧光610 nm）4)微循环图像观测器的研制（波长545 nm）通过这些进展，我们证实心肌代谢成像成为可能。在评价了该系统的性能后，我们首先将该系统应用于猪和犬的实验。通过NADH荧光获得代谢图像，通过灌注特异性结合毛细血管内皮细胞α2受体的分子血流示踪剂，测量数字x线图上毛细血管血流分布。其次，在控制和心肌缺血条件下，我们在心内膜微循环区域进行代谢成像。我们比较了100 mmHg灌注压控制条件和40、60 mmHg低灌注压缺血条件下NADH荧光强度、冠状动脉微血管直径和血流分布。再灌注和低氧灌注时NADH荧光分布呈斑片状分布，具有异质性。两幅图像的斑块面积都在几百微米左右。综上所述，NADH荧光与血流分布存在显著相关性，说明代谢功能分布与血流分布具有相似性。

We made in-vivo analysis on images of metabolic function and oxygen partial pressures in endocardial microcirculation where is the most frequent site of myocardial ischaemia. The purpose of the present study was to elucidate coronary microcirculation pathophysiologically. We achieved ;1) development of needle lens2) development of an NADH excitor and its fluorescence observer(excitation at 370 nm, fluorescence at 460 mm)3) development of Pd-porphine excitor and its fluorescence observer(excitation at 545 nm, fluorescence at 610 nm)4) development of micro-circulation image observer(wave length : 545 nm)With these developments, we confirmed that myocardial metabolism imaging was made possible.After evaluating the performance of the developed intra-vital needle microscope, we firstly applied this system to porcine and canine experiments. Obtaining metabolism images by NADH fluorescence, capillary blood flow distribution of digital radiogram was measured by perfusing molecular blood flow tracers, which specifically bind to α2 receptors of capillary endothelial cells.Secondly, we performed metabolism imaging at the region of endocardial microcirculation under the conditions of control and myocardial ischaemia. We compared NADH fluorescence intensity, coronary micro-vascular diameters and blood flow distribution under the control condition of 100 mmHg perfusion pressure and under the ischaemic condition of low perfusion pressure at 40 and 60 mmHg. There was heterogeneity with patchy pattern in NADH fluorescence distribution during reperfusion and hypoxic perfusion.. The sizes of patchy area in both images are about several hundred microns. In summary, there is a significant correlation between NADH fluorescence and blood flow distribution, indicating the similarity between metabolic function distribution and blood flow distribution.