胚胎小肠Cajal细胞的发育研究

目的研究人胚胎小肠cajal细胞的发育变化规律。方法采用全层铺片结合切片的免疫细胞化学技术。结果Cajal细胞呈酪氨酸激酶受体(Kit)和波形蛋白(vinlentin)免疫反应阳性。在胚胎发育早期，cajal细胞较少，为单层，稀疏分布于肌间神经丛周围，细胞为梭形，可见两个短而小的突起，未见分支；随着胎龄的增加，Cajal细胞数量增多，胞体增大，突起伸长，并出现分支。此时，肌间神经丛周围的Cajal细胞出现两层，其长轴彼此垂直，分别平行于环行肌和纵行肌。与此同时环行肌层内亦可见少许Cajal细胞；出生前，肌间神经丛部位的Cajal细胞接近成熟，两层细胞的突起进一步增多、伸长，彼此间形成与成人相似的完整的细胞网络。此时深肌丛附近亦可见少量Cajal细胞。结论人的小肠Cajal细胞发育有一定的时间顺序，即肌间神经丛周围最先出现，肌内次之，深肌丛较晚，出生前肌间神经丛周围的Cajal细胞已经接近成熟。这种发育演变若发生异常，可能导致某些胃肠动力障碍性疾病。

DEVELOPMENT OF INTERSTITIAL CELLS OF CAJAL IN FETAL SMALL INTESTINE

Objective To study the development of interstitial cells of Cajal(ICCs)in the human fetal small intestine. Method Immunocytochemicalstaining with whole-mount preparations and cryo-sections was used. Result At the early stageof the fetus, a few ICCs associated with the myenteric plexuswere seen inspindle-shape withtwo short processes.Their processes were often parallel to the circular smooth muscle and formed an incomplete network. With the increase in gestational age, the cell body enlarged and the processes elongated gradually. Many ICCs associated with the myenteric plexus tended to form two cellular networks:one ran parallel to the circular smooth muscle and the other parallel to the longitudinal muscle layer. At the same time, a few c-kit positive cells were observed within the circular muscle layer. At the late stage of the fetus, ICCs between the circular and longitudinal muscle layers appeared to be matureand form two completed cellular networks like those in adult human small intestine. Immunoreactive ICCs with weak staining werealso seen in the deep muscular plexus of the intestine. Conclusion The development ofthe phenotype ofICCsin the humanfetalsmall intestine seemed to follow such a sequence: ICCs appeared firstin the region of the myenteric plexus, then within the circular muscle layerand finally inthe deep muscular plexus of the gut. In the late phase of the fetus,ICCs associated with the myenteric plexus were almost mature,indicating that ICCs near the birth may possess the function ofcontrolling thegastrointestinal motility.