CONTROL OF PITUITARY GLAND AND PITUITARY TUMOR HORMONES

我们的研究集中在组织脂质在分泌过程中的作用， 调节催乳素和生长激素释放的过程。 的 磷脂酰肌醇的周转与催乳素密切相关 因为TRH对两者都有刺激作用，而多巴胺则是 抑制性的 磷脂酰肌醇的周转增加也是 与细胞内钙储存的释放相关， 分泌过程中必须的离子。 这些研究将被延长 确定磷脂代谢物在钙动员中的作用 和激素释放。 具体地说，甘油二酯的功能， 花生四烯酸和白三烯在这些过程中将被检查， 详细 我们有初步证据表明刺激花生四烯酸 产生和释放是分泌过程中的重要事件， 正常垂体细胞，这些研究将扩展到垂体 肿瘤细胞 我们有初步证据表明这些肿瘤细胞 在他们的钙处理缺陷，这导致他们的耐火性 多巴胺能抑制 这种可能性正在解决， 通过使用舞毒鱼毒素， 钙通道激活剂 我们相信我们可以恢复 多巴胺来抑制这种药剂释放催乳素。 我们推测 垂体瘤细胞对钙的处理异常减少， 与他们产生花生四烯酸的能力降低有关。 这个复杂 目前正在进行一系列调查。 （丙）

We have focused our research on the role of tissue lipids in the secretory processes regulating the release of prolactin and growth hormone. The turnover of phosphatidylinositol has been closely linked with prolactin release because TRH is stimulatory to both, whereas dopamine is inhibitory. An increased turnover of phosphatidylinositol is also correlated with the liberation of intracellular stores of calcium, an obligatory ion for the secretory process. These studies will be extended to determine the role of phospholipid metabolites in calcium mobilization and hormone release. Specifically, the function of diacylglycerol, arachidonate, and the leukotrienes in these processes will be examined in detail. We have preliminary evidence that stimulation of arachidonate production and release is an important event in the secretory process in normal pituitary cells, and these studies will be extended to pituitary tumor cells. We do have preliminary evidence that these tumor cells have a defect in their handling of calcium, and this leads to their refractoriness to dopaminergic inhibition. This possibility is being addressed by promoting an increase in calcium uptake through the use of maitotoxin, a calcium channel activator. We believe that we can restore the ability of dopamine to inhibit prolactin release by this agent. We speculate that the abnormally reduced handling of calcium by the tumor pituitary cells may relate to their reduced ability to produce arachidonate. This complex series of investigations is currently being implemented. (C)