Department of Cardiology, Longgang District Central Hospital of Shenzhen, Guangdong, China.
J Cardiol. 2012 Sep;60(3):242-7. doi: 10.1016/j.jjcc.2012.01.019. Epub 2012 Jun 15.
This study aimed to discover the pathogenesis of focal atrial fibrillation (AF) originating from pulmonary veins by observing the histological structure and special cells in the canine pulmonary vein model of persistent atrial fibrillation.
The pulmonary veins and the sinus node were obtained from 10 mongrel dogs (5 AF and 5 control group). Light microscopy, transmission electron microscopy, and immunohistochemistry were applied to transverse sections of each pulmonary vein and sinoatrial node. Morphological and distribution analyses were performed manually and automatically.
Cardiomyocyte progenitor (CMPs) and interstitial cells of Cajal (ICCs) showing typical features of either very immature or developing cells were found in the pulmonary vein sections of all animals subjected to experimental AF but not in the control group. The cells were mainly identified in sections with a thick muscular sleeve. A positive immunostaining of CMPs was also demonstrated; the staining characteristic was similar to that of P cells in the sinoatrial node, suggesting that these cells may function in a pacemaker capacity.
We demonstrated that pulmonary veins can host cardiac stem cell niches. Continuous rapid pacing can induce the differentiation of CMPs and ICCs, and CMPs may underlie the pacemaker activity of isolated pulmonary veins.
本研究旨在通过观察持续性心房颤动犬肺静脉模型中的组织学结构和特殊细胞，探究局灶性心房颤动（AF）的发病机制。
从 10 只杂种犬（5 只 AF 组和 5 只对照组）中获取肺静脉和窦房结。对每根肺静脉和窦房结的横切面进行光镜、透射电镜和免疫组织化学检查。手动和自动进行形态和分布分析。
在所有接受实验性 AF 的动物的肺静脉切片中都发现了心肌细胞祖细胞（CMPs）和 Cajal 间质细胞（ICCs），它们表现出非常不成熟或发育中的细胞的典型特征，但在对照组中未发现。这些细胞主要存在于肌袖较厚的切片中。CMPs 的免疫染色也呈阳性，染色特征与窦房结中的 P 细胞相似，提示这些细胞可能具有起搏器功能。
我们证明了肺静脉可以容纳心脏干细胞龛。持续快速起搏可诱导 CMPs 和 ICCs 的分化，CMPs 可能是肺静脉孤立起搏活动的基础。
