Wiemann M, Ehret G
Abteilung Vergleichende Neurobiologie, Universität Ulm, Germany.
Cell Tissue Res. 1993 Jul;273(1):79-87. doi: 10.1007/BF00304614.
Immunoreactive oxytocin is expressed by thymic epithelial cells, which share properties with neuroendocrine cells. In order to investigate the assumed paracrine secretion of oxytocin, we studied the subcellular localization of immunoreactive oxytocin within thymic tissue and cultured thymic epithelial cells of the male mouse. Three types of immunoreactive cells were distinguished with the electron microscope. Immunoreactive oxytocin was found to be restricted to the cytoplasm by the use of pre- and postembedding methods. Some epithelial cells, especially in the cortex, showed a pronounced labelling of vesicular membranes and membrane tubules of the endoplasmic reticulum. In some cells, keratin filaments were associated with the electron-dense stain. Under culture conditions immunoreactive cells of different shapes were found, all displaying similar patterns of labelling. The contents of different types of vacuoles were only rarely labelled. A special class of immunoreactive exocytotic vesicles could not be identified. Thus, our results do not support neuroendocrine secretion of oxytocin via vesicles of thymic epithelial cells but offer alternative modes of secretion.
免疫反应性催产素由胸腺上皮细胞表达，胸腺上皮细胞具有与神经内分泌细胞相同的特性。为了研究催产素假定的旁分泌分泌，我们研究了雄性小鼠胸腺组织和培养的胸腺上皮细胞中免疫反应性催产素的亚细胞定位。通过电子显微镜区分出三种免疫反应性细胞。使用包埋前和包埋后方法发现免疫反应性催产素局限于细胞质中。一些上皮细胞，尤其是皮质中的上皮细胞，内质网的泡状膜和膜小管显示出明显的标记。在一些细胞中，角蛋白丝与电子致密染色有关。在培养条件下，发现了不同形状的免疫反应性细胞，所有细胞都显示出相似的标记模式。不同类型液泡的内容物很少被标记。未鉴定出一类特殊的免疫反应性胞吐小泡。因此，我们的结果不支持通过胸腺上皮细胞的小泡进行催产素的神经内分泌分泌，而是提供了其他分泌模式。
