LAMINAR STRUCTURE OF THE HEART - VENTRICULAR MYOCYTE ARRANGEMENT AND CONNECTIVE-TISSUE ARCHITECTURE IN THE DOG
LAMINAR STRUCTURE OF THE HEART - VENTRICULAR MYOCYTE ARRANGEMENT AND CONNECTIVE-TISSUE ARCHITECTURE IN THE DOG
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DOI：
10.1152/ajpheart.1995.269.2.h571
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发表时间：
1995-08-01
影响因子：
4.8
通讯作者：
HUNTER, PJ
中科院分区：
文献类型：
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作者：
LEGRICE, IJ;SMAILL, BH;HUNTER, PJ
我们研究了犬心脏心室肌细胞及相关细胞外结缔组织基质的三维排列。四个心脏钾停搏，切除，并灌注固定在零跨壁压。在一系列精确定位的部位从右心室壁和左心室壁切下全层节段。在1）透壁切面和2）与心外膜表面相切的平面中，通过肉眼观察和扫描电子显微镜观察形态。所有标本的外观均与肌细胞有序的层状排列一致，肌层之间具有广泛的分裂面。这些平面在透壁切面上自心内膜向心外膜呈放射状排列，在切线切面上与局部肌纤维方向一致。体视学技术被用来量化这个组织的各个方面。肌层（48.4 +/- 20.4 μ m厚，4 +/- 2个肌细胞）的细胞组织在透壁或不同心室区域（6个节段中的23个部位）中没有一致的变化，但相邻层之间的耦合存在显著的透壁变化。层间分支的数量减少了两倍，从心外膜到中壁，而连接肌层的肌束膜胶原纤维的长度分布是最大的中壁。我们的结论是，心室心肌不是一个均匀的分支连续，但层状层次结构中，它是可能的，以确定在任何一点的材料对称的三个轴。
We have studied the three-dimensional arrangement of ventricular muscle cells and the associated extracellular connective tissue matrix in dog hearts. Four hearts were potassium-arrested, excised, and perfusion-fixed at zero transmural pressure. Full-thickness segments were cut from the right and left ventricular walls at a series of precisely located sites. Morphology was visualized macroscopically and with scanning electron microscopy in 1) transmural planes of section and 2) planes tangential to the epicardial surface. The appearance of all specimens was consistent with an ordered laminar arrangement of myocytes with extensive cleavage planes between muscle layers. These planes ran radially from endocardium toward epicardium in transmural section and coincided with the local muscle fiber orientation in tangential section. Stereological techniques were used to quantify aspects of this organization. There was no consistent variation in the cellular organization of muscle layers (48.4 +/- 20.4 mu m thick and 4 +/- 2 myocytes across) transmurally or in different ventricular regions (23 sites in 6 segments), but there was significant transmural variation in the coupling between adjacent layers. The number of branches between layers decreased twofold from subepicardium to midwall, whereas the length distribution of perimysial collagen fibers connecting muscle layers was greatest in the midwall. We conclude that ventricular myocardium is not a uniformly branching continuum but a laminar hierarchy in which it is possible to identify three axes of material symmetry at any point.