Analysis of paracrine regulation of endocrine gland function

垂体前叶细胞产生和分泌至少五种激素，这些激素在调节生长、代谢、生殖和免疫等方面具有重要作用。众所周知，垂体前腺细胞受下丘脑因子的调控。垂体前腺细胞对雌激素治疗、去势等生理变化也有反应，发生肥大、增生。然而，垂体前叶细胞的这些后期动态变化不能完全由下丘脑因素来解释。旁分泌调节可能对分泌细胞的调节起重要作用。卵泡星状细胞以其较长的细胞质突起包围着邻近的分泌细胞，被认为是对腺体细胞的分泌调节最重要的细胞。本研究发现，FS细胞在一种下丘脑因子PACAP的调控下产生IL-8和巨噬细胞集落刺激因子。这些细胞因子的产生在脂多糖（LPS）的刺激下显著增加。脂多糖还能刺激催乳素的分泌。这些结果表明，作为免疫系统信号的细胞因子在一定程度上是由分泌激素的垂体细胞通过旁分泌调节来控制的。

The anterior pituitary gland cells produce and secrete at least five kinds of hormones which are important for the regulation of growth, metabolism, reproduction and immunity. It is well known that the anterior pituitary glandular cells are regulated by hypothalamic factors. The anterior pituitary glandular cells also respond to some physiological changes such as the estrogen treatment and castration etc. and undergo hypertrophy and hyperplasia. These later dynamic changes of the anterior pituitary gland cells however can not be explained solely by hypothalamic factors. It has been postulated the paracrine regulation may be important for the regulation of the secretory cells. The folliculo-stellate cells which surround neighboring secretory cells with their long cytoplasmic processes are considered as the most important cells for the pracrine regulation of the glandular cells. In this research we found that the FS cells produce IL-8 and macrophage colony stimulating factors under the regulation of a hypotharamic factor, PACAP.The production of these cytokines was significantly increased by the stimulation of lipopolysaccharide (LPS). LPS also stimulates the secretion of prolactin cramatically. These results suggest that the cytokines, which are known as the signals of the immune system, are controled to some degree by hormone-secreting pituitary cells through paracrine regulation.