猪肺静脉肌袖组织的超微结构研究

Ultrastructural study of the pulmonary veins in pigs

目的利用电子显微镜观察肺静脉肌袖组织的超微结构,初步探讨肺静脉原性心房颤动的发病基础。方法5个月健康家猪3只,取其肺静脉,垂直肺静脉长轴切成2mm宽度的连续环状组织块,单号组织块用10%中性福马林固定确定电镜取材部位。双号用3%戊二醛固定,常规电镜标本制备。结果电子显微镜观察显示,猪肺静脉肌袖组织中含有两种特殊的细胞。(1)与窦房结的P细胞相似的P样细胞:①胞质清亮,电子密度低;②胞质中肌原纤维少而短小,杂乱地分布于细胞膜附近;(2)移行细胞:其形态细长,体积小,含有较多的趋向于沿长轴排列的肌原纤维。结论利用电子显微镜观察到猪肺静脉肌袖组织中存在与窦房结P细胞相似的P样细胞,对P样细胞的超微结构进行了详细描述,肺静脉内的异位起搏现象可能与P样细胞有关。

Objective To explore the possible relationship between the ultrastructural characteristics of pulmonary veins and the pathogenesis of atrial fibrillation originating from pulmonary veins. Methods The pulmonary veins from domestic pigs were serially sectioned （2 mm） transvemely along the vessels. The odd number sections were fixed in 10% phosphate buffered formalin solution and the even number sections were fixed in 3% Glutaral for further electron microscopy observations, Results Two cell types were found in the pulmonary veins of pigs. One cell type was the P-like cells that had an emptyappearing cytoplasm containing only sparse myofibrils and small mitochondria, both of which were randomly distributed. Another cell type was slender transitional cells with plenty of longitudinally displayed myofibrils. Conclusion P-like cells in the pig pulmonary veins were found using electron microscopy in this study and ectopic beats from P-like cells in the myocardial sleeves in the pulmonary veins might be responsible for atrial fibrillation originating from pulmonary veins.