Study on the function of folliculo-stellate cells in the anterior pituitary gland, especially the analysis of their secretory protein.

脑下垂体前叶由内分泌细胞和支持细胞组成。滤泡-星形细胞(FS-cell)是这些支持细胞的主要细胞成分，预计ES细胞在垂体前叶具有非常重要的功能。然而，FS细胞在垂体前叶的确切功能尚未确定。本研究的目的是研究毛囊星状细胞的功能。我们首先注意到在衰老的猪脑垂体中出现了大量PAS阳性胶体，我们的形态学研究表明，这些PAS阳性胶体完全被FS细胞包围。因此，胶体物质的表征对于分析FS细胞的功能可能是很重要的。幸运的是，我们已经成功地用猪脑下垂体纯化和分析了胶体，发现胶体中含有大量的聚集素。聚集素是一种高度糖化的蛋白质，推测它可能与脑神经细胞的凋亡有关。我们的免疫细胞化学研究表明，聚集素不是由FS细胞产生的，而是由一些内分泌细胞产生的。这些结果表明，产生Chusterin的细胞被FS细胞吞噬并被凋亡，聚集在胶体中的Clusterin作为残留体。脑下垂体内胶体的出现是众所周知的现象，但这是首次揭示了脑下垂体中胶体的化学成分，对于分析脑下垂体内簇状蛋白的生物学意义还有待进一步的研究。

The anterior pituitary gland is composed of endocrine cells and supportive cells. The folliculo-stellate cell(FS-cell) is the major cellular element of these supportive cells and expected that ES-cells have very important function in the anterior pituitary gland. However, the precise function of FS cells in the anterior pituitary gland has not been established. The purpose of this research project is a study of the function of folliculo stellate cells. We first noticed the appearance of large number of PAS positive colloid in the senescent porcine pituitary gland Our morphological study revealed that these PAS positive colloids were completely surrounded by the FS cells. Therefore, the characterization of the colloidal substance may be important for the analysis of FS cell function. Fortunately we have succeeded in purifying and analyzing the collois using the porcine pituitary gland and revealed the colloids contained large amount of clusterin. The clusterin is known as the highly glycosilated protein and suspected that it may be related to the neural cell apoptosis in the brain. Our immunocytochemical study showed clusterin is not produced by FS cells but some endocrine cells. These results suggest the cells produced chusterin were undergone to the apoptosis and phagocytosed by the FS cells and the clusterin accumulated in the colloid as the residual body. The colloid appearance in the pituitary gland is well known phenomenon however this is the first study which revealed the chemical component of those colloids, For the analysis the biological significance of the clusterin appearance in the pituitary gland is need further study.