c—kit阳性细胞和胎儿食管平滑肌发育的关系

c-kit-positive cells associated with development of smooth muscle in human fetal esophagus

目的：探讨c-kit阳性细胞和旷平滑肌肌动蛋白阳性平滑肌细胞（a-SMA）在人胎儿食管中分布关系。方法：采用免疫荧光组织化学双重标记法对8例胎儿食管中c—kit阳性细胞和a-SMA阳性平滑肌细胞的分布进行观察。结果：c-kit阳性细胞在食管上段内肌层内侧有少量分布，肌间层和黏膜下层也可见零星分布，在食管中段外肌层开始有少量分布，内肌层数量中等，至食管下段内外肌层均有大量分布。a-SMA阳性平滑肌细胞在食管肌层由上至下逐渐增加，并由内肌层扩展到外肌层。在食管上端肌问层和黏膜下层可见少量c—kit和a—SMA共同表达。结论：c—kit阳性细胞可能是Cajal问质细胞，在胎儿食管的分布与平滑肌密切相关。食管内平滑肌细胞和Cajal间质细胞可能起源于同一种前体细胞。

To investigate the distribution of c-kit-positive cells and a-smooth muscle actin （a-SMA） positive smooth muscle cells in human fetal esophagus. Methods： Immunoreactivity of c-kit and a-SMA in the esophagus of 8 human fetuses （26 4±3 weeks gestational age; 6 males and 2 females） was detected using double immunofluorescence staining method. Results： In the upper third of the esophagus, c-kit-positive ceils were detected in the most inner muscular layer, and some were also observed in the submucosal and myenteric plexus regions. In the middle third, c-kit-positive cells were detected in both inner and outer muscular layers but the number in the inner layer appeared more than that in the outer layer. The c-kit-positive cells were abundant in both layers in the lower third. The expression of a-SMA was detected in the most inner muscle layer at the upper third of the esophagus and then gradually increased downward and outward. The coexpression of c-kit and a-SMA was found in some cells at submucosal and myenteric plexus regions in the upper third of esophagus. Conclusion： The results suggest that c-kit-positive cells are probably the interstitial cells of Cajal and the distribution of c-kit- positive cells has close relationships with smooth muscle cells in the human fetal esophagus. Interstitial cells of Cajal and smooth muscle cells may develop from the same precursor cells in the esophagus.