权益分类	功能权益	普通用户	{{item.name}}会员
{{category.name}}	{{benefitItem.name}}

Histochemical and molecular biological studies on the physiological roles of the caudal neurosecretory system

尾神经分泌系统生理作用的组织化学和分子生物学研究

基本信息

批准号：
03640635
负责人：
ICHIKAWA Tomoyuki
金额：
$ 1.28万
依托单位：
TOKYO METROPOLITAN INSTITUTE FOR NEUROSCIENCE
依托单位国家：
日本
项目类别：
Grant-in-Aid for General Scientific Research (C)
财政年份：
1991
资助国家：
日本
起止时间：
1991 至 1992
项目状态：
已结题

项目摘要

The caudal neurosecretory system (CNS) synthesizes and releases at least two peptide hormones, urotensins I and II (UI and UII). While these neuropeptides have been shown to have a wide variety of biological activities, a clear picture of their coordinated functions in fish has not yet emerged. The sequencing of these peptides by us and others has broadened our thinking about their possible functions since UI and UII have been found to have sequence homology to corticotropin-releasing factor (CRF) and somatostatin, respectively. Taking the possible hypophysiotropic functions of UI and UII into consideration, we carried out histochemical and molecular biological studies to elucidate the physiological functions of the CNS.First, we synthesized UI and UII, and developed radioimmunoassays for both peptides. This enables us to measure contents of UI and UII in the CNS and other tissues. Second, we established an in situ hybridization (ISH) histochemistry for UI and UII, which has the advantage of great specificity in terms of both the genetic information expressed and identification of the cells in which that information is expressed. We demonstrated that UI and UII are expressed in almost all identifiable caudal neurosecretory neurons. Further, we found that UI is expressed in the hypotalamic nuclei, the locations of which differ from those of CRF-producing neurons. This strongly suggests that UI has a hypophysiotropic function. Third, we also established a method for identification of UI transcripts and UI peptides in the same neurons by combined ISH and immunohistochemistry. This provides information on the dynamic aspects of gene expression, and synthesis and release of hormones.Using the methods mentioned above, we are now investigating changes in the gene expressions and contents of UI and UII in various tissues in normal and hypophysectomized fish subjected to various environments and conditions to elucidate the hypophysiotropic functions of UI and UII.

尾部神经分泌系统（CNS）合成并释放至少两种肽类激素，即尿紧张素I和II（UI和UII）。虽然这些神经肽已被证明具有广泛的生物活性，但它们在鱼类中的协调功能的清晰图像尚未出现。我们和其他人对这些肽的测序拓宽了我们对它们可能功能的思考，因为已经发现UI和UII分别与促肾上腺皮质激素释放因子（CRF）和生长抑素具有序列同源性。考虑到UI和UII可能具有的促垂体功能，我们进行了组织化学和分子生物学研究，以阐明CNS的生理功能。首先，我们合成了UI和UII，并对这两种肽进行了放射免疫分析。这使我们能够测量中枢神经系统和其他组织中UI和UII的含量。其次，我们建立了原位杂交（ISH）组织化学UI和UII，这具有很大的特异性的优势，在表达的遗传信息和识别的细胞中，该信息被表达。我们证明，UI和UII表达在几乎所有可识别的尾神经分泌神经元。此外，我们发现UI在下丘脑核中表达，其位置与产生CRF的神经元的位置不同。这强烈表明UI具有促垂体功能。第三，我们还建立了一种方法，用于鉴定UI转录本和UI肽在同一神经元中的ISH和免疫组织化学相结合。利用上述方法，我们正在研究UI和UII在正常和垂体切除后的鱼的各种组织中的基因表达和含量在各种环境和条件下的变化，以阐明UI和UII的促垂体功能。