REGULATION OF CCK AND GRP MRNA AND METABOLISM

多种神经肽参与胃肠运动的中枢调控。 肠道(GI)功能。在这些多肽中(定位于 中枢神经系统神经元)是CCK(CCK；CCK-8；CCK-(26-33))和胃泌素- 释放肽(GRP-(1-27))。这些多肽发挥的作用是 与调节其生物合成和新陈代谢的机制有关。 由于多肽前体的生物合成速率通常是确定的 通过它们编码的mRNA的细胞内容，以及由 与其新陈代谢相关的特定多肽酶，洞察 CCK和GRP mRNA水平及CCK和GRP的调控机制 神经系统中的新陈代谢可以进一步阐明生理学 CCK和GRP(及相关多肽)在脑内的作用 胃肠道功能的调节和控制。因此，中央 这个项目的问题是：CCK mRNA和GRP mRNA水平如何与CCK 神经系统中的GRP代谢受到调控吗？ 我们的假设是，基因表达和代谢酶相关 产生CCK和GRP的神经元可以受到递质的影响， 神经肽和类固醇激素。递质和多肽结合到 膜受体和激活细胞内信使系统，而 类固醇激素有细胞内的可溶性受体。具体目标 是(1)表征哪些第二信使系统影响 CCK和GRP mRNA、蛋白水解酶水平及CCK和GRP水平 GRP(包括各种形式)；(2)表征哪些具体 蛋白水解酶参与细胞内CCK和GRP的代谢 以及在体内；(3)哪些递质和神经肽参与 调节这些作用，以及(4)哪些类固醇激素调节CCK mRNA 以及GRP基因表达水平和代谢酶活性。为了达到这些目标， CCK mRNA、GRP mRNA和代谢酶的调节 在克隆人神经母细胞瘤细胞系(来源于自主神经)中的细胞内 神经系统)，具有高水平的CCK和GRP基因表达 在刺激时和在大鼠脑内体内分泌CCK。通过组合 信使核糖核酸测定、CCK和GRP水平及代谢酶测定 都非常有信心，我们将成功地确定CCK和 GRP在神经系统中受到调节。

A variety of neuropeptides are involved in the central control of gastro- intestinal (GI) functions. Amongst these peptides (which are localized in CNS neurons) are cholecystokinin (CCK; CCK-8; CCK-(26-33)) and gastrin- releasing peptide (GRP-(1-27)). The role which these peptides play is linked to the mechanisms which regulate their biosynthesis and metabolism. Since the biosynthetic rates of peptide precursors are generally determined by cellular contents of their encoding mRNAs, and metabolic rates by the specific peptidases associated with their metabolism, insight into the mechanisms controlling CCK mRNA and GRP mRNA levels and CCK and GRP metabolism in neuronal systems can further elucidate the physiological roles of CCK and GRP ( and related peptides) in the brain with respect to regulation of GI tract function and control. Therefore, the central question of this project is: how are CCK mRNA and GRP mRNA levels and CCK and GRP metabolism regulated in neuronal systems? Our hypothesis is that gene expression and metabolic enzymes associated with CCK- and GRP-producing neurons can be affected by transmitters, neuropeptides and steroid hormones. Transmitters and peptides bind to membrane receptors and activate intracellular messenger systems, while steroid hormones have intracellular soluble receptors. The specific aims are (1) to characterize which second messenger systems influence levels of CCK mRNA and GRP mRNA, levels of proteolytic enzymes and levels of CCK and GRP (including various forms); (2) to characterize which specific proteolytic enzymes are involved in the metabolism of CCK and GRP in cyto and in vivo; (3) which transmitters and neuropeptides are involved in regulating these effects, and (4) which steroid hormones regulate CCK mRNA and GRP mRNA levels and metabolic enzymes. To meet these aims, the regulation of CCK mRNA and GRP mRNA and metabolic enzymes will be studied in cyto in a clonal human neuroblastoma cell line (derived from autonomic nervous system) which has high levels of CCK and GRP gene expression secretes CCK upon stimulation and in vivo in the rat brain. By combining mRNA measurements, CCK and GRP levels and metabolic enzyme measurements we are very confident that we will be successful in determining how CCK and GRP are regulated in neuronal systems.