犬心房室隔内细胞形态学特征

The study of cellular morphologic feature in canine atrioventricular septum

目的 通过观察犬心房室隔内细胞形态学特征 ,探讨其可能的功能意义。方法 利用光学显微镜 ,通过HE和Masson染色对犬心房室隔标本的细胞形态、排列方式、直径和染色深浅进行细致观察 ,通过透射电镜观察证实光镜所见细胞特征。结果 ①心房扩展部可见到四条过渡细胞束与房室结相连 :Ⅰ径自冠状窦壁沿锥形间隙或室间隔肌与右房肌之间向前至房室结后端 ;Ⅱ径自冠状窦口周围沿右房心内膜下至房室结浅层 ;Ⅲ径经三尖瓣隔侧瓣与冠状窦口之间向前经心内膜下至房室结右后端并至房室结的浅层 ;Ⅳ径自左侧心房肌向右下沿室间隔肌上缘至房室结左后端。低倍镜下纤维排列较疏松 ,纤细 ,直径约 9.5 μm ,染色浅淡。高倍镜下细胞呈长形 ,核长圆形与细胞长轴方向一致 ,细胞质染色淡。电镜下细胞特征符合过渡细胞特点。②冠状窦周围见到大量T细胞和少量P细胞及浦肯野细胞。结论 犬心房室隔内有过渡细胞构成的新传导径路 ;

Objective To observe the cellular morphologic feature in canine atrioventricular septum and discuss its possible functional significance.Methods By staining with H-E and Masson trichrome stain, and using light microscope we observed cellular shape, arrangement, diameter and dyeing level in canine atrioventricular septum, and confirmed cellular ultrastructural feature through electron microscope. Results ①Four T cell bundles were found linked to AVN in canine atrium extending. The first path was from CS along cone crevice or between IVS and RA forward to reach the posterior margin of AVN; the second path was from CSO beneath endocardium of RA to the superficial layer of AVN; the third path way was between the sptal cusp of the tricuspid valve and CSO, forward through the endocardium to right posterior border of AVN and superficial layer of AVN; and the fourth path way was from LA forward inferior along superior border of IVS to left posterior of AVN. Under low multiple microscope, fibers arranged thin and loosely with their diameter about 9.5μm, dyeing tasteless; under high multiple microscope, fibres showed long shape with their long nuclear and they accorded with cell's long axis, cytoplasm dyeing tasteless. The cellular ultrastructural feature of these cell bundles accorded with that of transition cells. ②A lot of T cells and a few P cells would be seen around CS.Conclusion ①There are T cells that make up to new conduction pathways in canine atrioventricular septum.② It is possible that CS is an important latent pacemaker.