摘要
用扫描电镜、透射电镜及光镜组化方法观察成年健康Balb/c小鼠肠道Peyer淋巴集结圆顶部表面上皮中M细胞的形态结构和分布及其表面组化特性。结果表明,M细胞是分布于Peyer淋巴集结圆顶部表面上皮中的一种特殊的上皮细胞。其形态结构特征为游离面具有许多短的微绒毛和微皱褶,基部胞膜内陷形成1个大的中央腔,其腔内常包绕数个淋巴细胞,偶见浆细胞和巨噬细胞,顶部胞质终末网不发达,有许多小泡。M细胞表面低活性的碱性磷酸酶可作为光镜下鉴别M细胞的依据。
The structure and distribution of Peyer's patch M cells of adult Balb/c micewere studied by scanning and transmission electron microscopy. Alkaline phosphatase (ALP)of the epithelium covering mouse-Peyer's patches were examined by using histochemicaltechniques.The results of scanning electron microscopy showed that there were 4-10 dome areasper one Peyer's patch and several dozens of M cells interspersed among the absorptive-likeepithelial cells of every dome area. Lymphocytes were frequently seen on the surface ofM cells. On transmission electron microscope observations, there were irregular, shortand thick microvilli but fewer in number, and some microfolds on the surface of the Mcells. The underlying terminal web was poorly developed and the apical cytoplasm devoidof organelles and contained many vesicles and some small lysosomes. The cytoplasminvaginated deeply from the basal part into the cell center forming a large central cavitywhich usually enfolded 1-5 lymphocytes and a few plasma cells or macrophages. The M cellsshared tight junctions and desmosomes with adjacent epithelial cells. Histochemical studiesof the follicle-associated epithelium indicated that the apical membrane of M cells hadobviously less ALP than that of absorptive cells.
