SECRETION OF TRH & OTHER NEURAL PEPTIDES

这项研究的长期目标是确定 调节的生理、细胞和分子机制 含有255个氨基酸的多聚蛋白ProTRH的加工 5份促甲状腺激素相关激素(TRH)前体 序列两侧是成对的碱性残基，分泌的是 在TRH及其前激素发生的不同区域。 该项目的具体目的是阐明：i)性质 PRTRH加工的中间体和最终产品 用脉冲追踪法研究转染An基因的肿瘤细胞系 含前促TRH基因的表达载体及其在围产期大鼠中的表达 单层培养中的胰腺；ii)基础的机制 PRTRH在脑内特定区域的正常加工模式 中枢神经系统及其调节；iii)甲状腺轴和 调节PRTRH过程的单胺能输入及其机制 体内下丘脑随后分泌TRH的途径是 垂体门静脉插管。立体定向植入 在两个垂体部交界处的推拉套管 茎和嗅球将使这种调节成为可能。 而它的细胞特异性将被表征为非应激 通过直接比较下丘脑和 另一个CNS地点。四)自分泌和旁分泌的作用 调节TRH和其他PRTRH分泌的因素- 从朗格汉斯胰岛衍生的多肽将被确定 在单层培养中使用胎儿/新生儿胰腺。v) 组氨酰-脯氨酸二酮-哌嗪含量的测定 (HisProDKP)是从ProTRH直接派生而来的，而不需要事先 TRH的形成，这种具有生物活性的环化二肽 将在转基因细胞系和大鼠体内鉴定 放射免疫法检测链脲佐菌素治疗后的胰岛 免疫组织化学和原位杂交。 这项研究将提供有关合成和 生物活性多肽在神经内分泌中的代谢 哺乳动物的系统，与哺乳动物的病理生理学有关 神经系统、下丘脑-垂体疾病与糖尿病 人类患上了糖尿病。

The long-term objectives of this research are to determine the physiologic, cellular and molecular mechanisms regulating the processing of proTRH, a 255 amino acid polyprotein which contains 5 copies of a thyrotrophin-relating hormone (TRH) progenitor sequence flanked by paired basic residues, and the secretion of TRH in the various regions where TRH and its prohormone occur. The specific aims of the project are to elucidate: i) the nature of the intermediates and final products of proTRH processing using pulse-chase studies in tumor cell lines transfected with an expression vector containing preproTRH cDNA and in rat perinatal pancreas in monolayer culture; ii) the mechanisms underlying the normal pattern of proTRH processing in specific regions of the CNS and its regulation; iii) the role of the thyroid axis and monoaminergic input in regulating proTRH processing and the subsequent secretion of TRH form the hypothalamus in vivo by hypophysial portal vessel cannulation. Stereotactic implantation of push-pull cannulae in both the pituitary, at the junction of the stalk, and in the olfactory bulb, will enable such regulation and its cellular specificity to be characterized in nonstressed awake animals by direct comparison of the hypothalamus with another CNS location. iv) The role of autocrine and paracrine factors in regulating the secretion of TRH and other proTRH- derived peptides from the Islets of Langerhans will be determined using fetal/neonatal pancreas in monolayer culture. v) Determination of whether histidyl proline diketopiperazine (HisProDKP) is derived directly from proTRH without prior formation of TRH, this biologically active cyclized dipeptize will be characterized in transfected cell lines and in rat pancreatic islets following streptozotocin treatment by RIA, immunohistochemistry and in situ hybridization. This research will provide information on the synthesis and metabolism of biologically active peptides in the neuroendocrine system of mammals and has relevance to the pathophysiology of nervous system, hypothalamic-pituitary disorders and diabetes mellitus in man.