Ultrastructural study of the pulmonary veins in pigs / 中华心血管病杂志

ABSTRACT

<p><b>OBJECTIVE</b>To explore the possible relationship between the ultrastructural characteristics of pulmonary veins and the pathogenesis of atrial fibrillation originating from pulmonary veins.</p><p><b>METHODS</b>The pulmonary veins from domestic pigs were serially sectioned (2 mm) transversely 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.</p><p><b>RESULTS</b>Two cell types were found in the pulmonary veins of pigs. One cell type was the P-like cells that had an empty-appearing 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.</p><p><b>CONCLUSION</b>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.</p>