大鼠颌下腺肌上皮细胞分化的体内研究

Differentiation of Myoepithelial Cells of the Rat Submandibular Gland in Vivo

目的 :对大鼠颌下腺肌上皮细胞发育分化进行研究。方法 :采用光镜、电镜和免疫组化染色等方法 ,对胚胎 17、18、19、2 0、2 1d及生后 1、5、10、15、2 0d的Wistar大鼠颌下腺肌上皮细胞进行观察。结果 :17d时肌上皮细胞为尚未分化。胚胎 18d ,可见肌上皮样细胞及分泌细胞。肌上皮细胞位于腺上皮与基底板之间 ,呈梭形。胚胎 2 1d出现细小的肌微丝。生后 1d ,胞浆内可见较明显肌微丝 ,免疫组化染色显示有少量Actin阳性细胞。生后 15d ,Actin阳性细胞明显增多。生后 2 0d ,肌上皮细胞趋于成熟 ,胞浆内含有大量的、与细胞长轴平行的肌微丝 ,胞膜内侧可见吞饮小泡。Actin强阳性的细胞数量明显增多。结论 :大鼠颌下腺肌上皮细胞与腺上皮细胞同时分化 ;其细胞内细胞器的发育有一定的规律 ;肌上皮细胞可能来源于终末导管复合体。

Objective:To study the differentiation of the myoepithelial cells of rat submandibular glands in vivo.Methods:The samples were used for light microscopy,electron microscopy and immunohistochemistry at daily intervals from 17 days in utero, through 1 day at birth, and at 5,10,15,20 days post partum.Results:Through 17 days in utero, the epithelial cells of the glandular rudiment are relatvely undifferentiated.At 18 days, Presumptive myoepithelial cells were first seen coinciding with the onset of secretion.These cells were enlongated, peripherally located and subjacant to the epithelial basal lamina.Initial deposition of cytofilaments in the myoepithelial cells was observed as early as 21 days of gestation.There were actin-positive cells at 1 day after birth.The number of Actin-positive cells obviously increased at 15 days after birth.Most matured myoepithelial cells were seen at 20 days following birth.Conclutions:Myoepithelial cells were first seen coinciding with the onset of secretion; the development of cellular organs is of specific regularity;myoepithelial cell might stem from terminal tubule complexs.