Armiger L C, Urthaler F, James T N
J Anat. 1979 Dec;129(Pt 4):805-17.
Right ventricular septomarginal trabeculae ('false-tendons') from puppies, young adult, and older adult dogs were examined by light and electron microscopy. The connective tissue of the trabeculae obtained from the puppies and the young adult dogs had few elastic fibres, but this component was well developed in the connective tissue of the adult dogs. The trabeculae of older dogs also showed scattered foci of extracellular fat droplets, and their junctional regions nearest to the ventricular wall were often heavily laden with fat. The Purkinje cells were uniform in each group, but differed from one group to another: in the puppies they resembled typical conducting cells, being predominantly cuboidal with few, poorly developed myofibrils, whilst in the adults the Purkinje cells resembled working myocytes, being elongated with a well developed complement of longitudinally arranged myofibrils. The cells of all age groups showed a complete absence of T-tubules, simply arranged interculated discs, and frequent dilatations of the sarcoplasmic reticulum. The cells of older dogs showed separations of the undifferentiated regions of most discs. Membrane degenerations and the presence of numerous fat droplets also were common. The fine structural cytology of Purkinje cells therefore appears to change considerable with age in the right ventricular septomarginal trabeculae ('false-tendons') of the dog heart.
对幼犬、成年幼犬和成年犬的右心室隔缘小梁（“假腱索”）进行了光镜和电镜检查。从幼犬和成年幼犬获得的小梁结缔组织中弹性纤维较少，但在成年犬的结缔组织中该成分发育良好。老年犬的小梁还显示出散在的细胞外脂肪滴灶，并且它们最靠近心室壁的连接区域通常充满脂肪。每组中的浦肯野细胞是均匀的，但组与组之间存在差异：在幼犬中，它们类似于典型的传导细胞，主要为立方形，肌原纤维少且发育不良，而在成年犬中，浦肯野细胞类似于工作心肌细胞，呈细长形，具有发育良好的纵向排列的肌原纤维。所有年龄组的细胞均完全没有T小管，闰盘排列简单，肌浆网频繁扩张。老年犬的细胞显示大多数闰盘的未分化区域分离。膜变性和大量脂肪滴的存在也很常见。因此，犬心脏右心室隔缘小梁（“假腱索”）中浦肯野细胞的精细结构细胞学似乎随年龄有相当大的变化。
