人胎儿喉黏膜上皮细胞的发育分化特点

目的]研究中国人胎儿喉黏膜上皮细胞发育分化的特点.方法]收集9～40周胎儿喉标本33例.应用连续切片HE染色、细胞角蛋白免疫组化染色、扫描电镜和透射电镜观察其黏膜上皮.结果]9周胎喉黏膜由1～2层低柱状细胞组成,仅表层细胞表达微弱的角蛋白,13周后出现多种类型的上皮细胞,上皮全层均表达细胞角蛋白;会厌舌面、声带被覆鳞状上皮,会厌喉面、室带、喉室及声门下区被覆假复层纤毛柱状上皮,其基底细胞和中间细胞的胞浆内含有丰富的胞浆泡状系统、张力原纤维和桥粒;过渡上皮和纤毛上皮中均散在岛状鳞状上皮但出现时间不一致.结论]人喉黏膜上皮细胞的分化发生于胎儿9～13周期间;纤毛上皮的基底细胞和中间细胞具有双向分化的潜能;过渡上皮和纤毛上皮中出现岛状鳞状上皮是生理现象,前者由复层立方上皮分化而来,后者由纤毛上皮分化而来.

Characterization of Development and Differentiation of Human Fetal Laryngeal Epithelial Cells

Objective] To investigate the characterization of the development and differentiation of Chinese fetal laryngeal epithelial cells. Methods] Thirty-three cases of 9-40 weeks fetal laryngeal specimens were collected. The laryngeal epithelium of these specimens were observed by light microscopy, cytokeratins immunohistochemistry and electron microscopy. Results] The laryngeal epithelium of 9 weeks human fetus was composed of monoplayer or stratified cuboidal cells, only the surface cells expressed weak cytokeratins. After 13 weeks, three types epithelium appeared and the epithelium expressed strong cytokeratins. The epithelial layer of the true vocal cord and the tongue surface of the epiglottis were composed of squamous epithelium and the other area were covered with pseudostratified ciliated columnar epithelium. Cytoplasmic vacuolar system, tonofilaments and desmosomes were observed in the based and the intermediate cells. Islands of squamous cells were found scattered in the transitional epithelium and the ciliated epithelium but the appeared time was different. Conclusion] Cell differentiation of human fetal laryngeal epithelium was accomplished during 9-13 weeks. The based and the intermediate cells of the ciliated epithelium possessed the ability of bipotential differentiation. Islands of squamous cells scattered in the transitional and the ciliated epithelium were physiologic in origin, the former originated from the stratified cube epithelium and the latter from the ciliated epithelium.