THREE-DEMENSIONAL MICROSTRUCTURE ABNORMALITY OF CORONARY CAPILLARY NETWORK AFTER MYOCARDIAL REPERFUSION

已知冠状动脉灌注不足在毛细血管网络水平上不均匀地发生，这取决于冠状动脉流量控制单元（FCU;几百ng长度）的最小尺寸。目的：应用激光共聚焦扫描显微镜（CLSM）研究心肌再灌注后冠状动脉微灌注模式和三维结构异常。采用开胸麻醉Wistar大鼠心脏，结扎左前降支7min，再灌注3min。将心脏分为两组：1）再灌注后静脉注射吲哚菁绿色染色良好的再灌注区[良好-再流]; 2）染色不良的再灌注区[无-再流]。采用LangendorfFs灌流模式进行离体心脏灌注。用造影剂[BaSO4+印度墨水+明胶]填充整个冠状动脉微血管。用CLSM [0.09 μ m~3/voxel]对两组的对照区[Ct; LCX区]和再灌注区[LAD区]进行三维观察。毛细管体积分数[CVF =毛细管体积/ [心肌体积+毛细管体积]是从三维图像上计算出来的与CT比较，两组再灌注区毛细血管直径和密度均减小，呈波浪状、皱缩状。与Ct相比，良好再流再灌注区的CVF显著降低40%[p <0.005]，无再流再灌注区的CVF进一步降低83%[p <0.001，vs. Ct，p <0.001，vs.良好再流]。无复流时，低灌注区呈不均匀分布，多个FCU低流量聚集。心肌再灌注后冠状动脉无复流表现为不均匀性毛细血管充盈减少，并伴有波形、皱缩等形态学改变。

Coronary perfusion insufficiency is known to occur heterogeneously at the capillary network level depending on the minimum size of coronary flow control unit (FCU ; several hundreds ng length). We aimed to investigate micro-perfusion pattern andthree-dimensional [3-D] structural abnormality of coronary capillary network after myocardial reperfusion using a con focal laser scanning microscopy (CLSM). Using opened-chest anesthetized Wistar rats' hearts, LAD was occluded for 7 min followed by 3 min reperfusion. The hearts were divided into two groups ; 1) well stained reperfused area by indocyanine green iv after reperfusion [Good-reflow], and 2) poorly stained group [No-reflow]. Then, the hearts were isolated and perfused by LangendorfFs mode. Entire coronary microvasculature was filled with contrast medium [BaSO4+Indian ink+gelatin]. Capillaries in the section [200um in thickness] were observed 3-dimensionaly using CLSM [0.09um3/voxel] for control area [Ct ; LCX region] and reperfused area [LAD region] in both reflow groups. Capillary volume fraction [CVF=capillary vol./[myocardial vol.+ capillary vol.] was computed from 3-D images. Comparing with Ct, reperfused area of both groups showed decreased capillary diameter and density with waving and shrinkage configuration. CVF was significantly reduced by 40% in the reperfused area of Good-reflow compared with Ct [p<.005], and further decreased by 83% in No-reflow [P<.001, vs. Ct, p<.001, vs. Good-reflow]. In No-reflow, the low perfusion area was distributed heterogeneously with similar low-flow clusterings of several FCUs lower flows. Coronary no-reflow after myocardial reperfusion was characterized by heterogeneous capillary filling reduction with morphological change such as waving and shrinkage.