Shimada T
Department of Anatomy, Jikei University School of Medicine, Japan.
Cell Tissue Res. 1992 Feb;267(2):251-60. doi: 10.1007/BF00302962.
Immunohistochemical localization of keratin, an intermediate filament protein, was studied in bull, goat, and sheep anterior pituitary glands, i.e., in animals of the order Artiodactyla. Strong immunoreactivity was detected in the cells of the marginal layer of bull and goat, as well as in cysts or large follicles in the anterior lobe of all 3 species. In addition, a number of stellate-shape cells were immunoreactive for keratin and were distributed throughout the anterior lobe. The localization of keratin-positive cells in light-microscopic preparations correlated precisely with the localization of folliculo-stellate cells in adjacent ultrathin sections. In ultrastructural studies, many slender and elliptical membranous components which were different from smooth endoplasmic reticulum were observed in the cytoplasm of the some keratin-positive cells. Some of the folliculo-stellate cells in the 3 species were also immunoreactive for the alpha subunit of S-100 protein, which exists in some epithelial cells. On the other hand, immunolocalization of glial fibrillary acidic protein, a glial cell marker, could not be demonstrated in the anterior pituitary glands of the 3 species studied. These results suggest that keratin-positive folliculo-stellate cells express epithelial-like characteristics.
在牛、山羊和绵羊的垂体前叶，即偶蹄目动物中，研究了中间丝蛋白角蛋白的免疫组织化学定位。在牛和山羊边缘层的细胞中，以及在所有3个物种前叶的囊肿或大滤泡中，检测到强免疫反应性。此外，一些星状细胞对角蛋白呈免疫反应性，并分布于整个前叶。光镜标本中角蛋白阳性细胞的定位与相邻超薄切片中滤泡-星状细胞的定位精确相关。在超微结构研究中，在一些角蛋白阳性细胞的细胞质中观察到许多细长和椭圆形的膜性成分，这些成分不同于滑面内质网。这3个物种中的一些滤泡-星状细胞对存在于某些上皮细胞中的S-100蛋白α亚基也呈免疫反应性。另一方面，在所研究的3个物种的垂体前叶中未显示神经胶质细胞标志物胶质纤维酸性蛋白的免疫定位。这些结果表明，角蛋白阳性的滤泡-星状细胞表达上皮样特征。
