NEUROPEPTIDE BIOSYNTHESIS AND METABOLISM IN THE CNS

神经肽现在被认为是化学物质的一个组成部分。 中枢神经系统的神经传递；然而，人们对此知之甚少 关于这类递质新陈代谢的调节。 拟议的研究旨在定义 特异性阿片肽脑啡肽的细胞内代谢 大鼠中枢神经系统内的投射系统。几个方面 脑啡肽代谢的研究将使用体内和体外两种方法 方法：(A)脑啡肽在投影中的利用率 苍白球的尾壳核和苔藓纤维系统 对照组和对照组均可检测到海马区颗粒细胞 受到生理或药物刺激的动物。这些数据将 结合前脑啡肽原诱导性变化的分析 以达到对脑啡肽含量的全面了解。 脑啡肽生物合成的调控。对于这些活体脉搏的研究 用放射性同位素氨基酸标记细胞体之后，将 放射性标记甲硫氨酸脑啡肽的纯化 终端领域使用顺序高效液相色谱。 (B)使用相同的体内标记技术，比活性 在容易释放的池中存在的多肽将在 无论是对照动物还是刺激动物。(C)酶的活性 负责甲硫氨酸脑啡肽的翻译后解放 前脑啡肽原将在纯化的分泌颗粒中进行研究 纹状体和来自对照和刺激的海马区 动物。从这些实验中获得的信息将是必不可少的。 在解释脑啡肽的潜在生理作用时 在这两个投影系统中的多肽，可以作为基础 检测其他中枢神经系统神经肽的代谢情况。

Neuropeptides are now recognized to be an integral part of chemical neurotransmission in the central nervous system; however, little is known regarding the regulation of the metabolism of this class of transmitters. The proposed research is directed toward defining the dynamics of the intracellular metabolism of the opiate peptide enkephalin in specific projection systems within the rat central nervous system. Several aspects of enkephalin metabolism will be studied using both in vivo and in vitro techniques: (a) the rate of enkephalin utilization in the projection from the caudate-putamen to the globus pallidus and in the mossy fiber system of hippocampal granule cells will be determined in both control and physiologically or pharmacologically stimulated animals. These data will be combined with an analysis of the induced changes in preproenkephalin mRNA and in enkephalin content to arrive at an overall understanding of the regulation of enkephalin biosynthesis. For these studies in vivo pulse labeling of cell bodies with radioisotopic amino acid will be followed by the purification of radiolabeled Met-enkephalin containing peptides from terminal fields using sequential high performance liquid chromatography. (b) Using the same in vivo labeling techniques, the specific activity of the peptides present in the readily releaseable pool will be determined in both control and stimulated animals. (c) The activity of the enzymes responsible for the post-translational liberation of Met-enkephalin from proenkephalin will be studied in secretory granules purified from the striatum and from the hippocampus from both control and stimulated animals. The information obtained from these experiments will be essential in interpreting the potential physiological roles for the enkephalin peptides in these two projection systems and can serve as a basis for examining the metabolism of other CNS neuropeptides.