EXTRAHYPOTHALAMIC AVP: SYNTHESIS AND SECRETION

脉络丛（Choroid plexus，CP）是脑脊液（cerebral fluid，CSF）的主要产生者，产生并分泌多种神经肽、生长因子和细胞因子到CSF中。 我们的一般工作假设是CP衍生的多肽不仅通过自分泌作用局部调节CP上皮的功能，而且还对脑中的靶细胞施加远端旁分泌作用。 由于CSF的持续产生和流动，可以通过CSF通路到达远端脑区。本申请的重点是精氨酸加压素（AVP）。CSF-AVP在促进脑水肿和血管痉挛中起重要作用，这些脑水肿和血管痉挛伴随着几种CNS疾病，包括创伤、蛛网膜下腔出血（SAH）和缺血。 然而，CSF AVP的来源和AVP释放到CSF中的调节尚不清楚。 我们以前的研究表明CP表氦可能是CSF AVP的来源。本提案的具体目的是深入了解1）脉络膜AVP基因表达的调节，2）促进CP上皮释放AVP的细胞内介质和神经激素促分泌素，以及3）该分泌过程的性质（通过调节或组成性途径）。我们将通过应用体内大鼠模型和体外CP上皮细胞培养来探讨上述问题。 AVP释放的功能实验将辅以分子和免疫化学分析，如逆转录酶-聚合酶链反应、蛋白质印迹和免疫细胞化学。 将使用放射免疫测定法定量AVP含量。长期的目标是获得一个全面的看法，如何CP-CSF系统调节神经元和神经胶质细胞的内部环境。 这些研究将为病理模型的开发奠定基础，从而为治疗CNS疾病（如创伤、SAH和卒中）提供有效的治疗方法。

Choroid plexus (CP), a major generator of cerebrospinal fluid (CSF), produces and secretes into the CSF various neuropeptides, growth factors, and cytokines. Our general working hypothesis is that the CP-derived polypeptides not only regulate the function of CP epithelium locally, by autocrine actions, but also exert distal paracrine effects on target cells in the brain. The distal brain regions may be reached through CSF pathways due to continual production and flow of CSF. The focus of this application is on arginine vasopressin (AVP). CSF-borne AVP plays an important role in promoting cerebral edema and vasospasm that accompany several CNS disorders, including trauma, subarachnoid hemorrhage (SAH), and ischemia. However, the sources of CSF AVP and the regulation of AVP release into the CSF are not well understood. Our previous studies have demonstrated that CP epihelium is a likely source of CSF AVP. Specific aims of the present proposal are to obtain an insight into 1) the regulation of choroidal AVP gene expression, 2) intracellular mediators and neurohormonal secretagogues promoting AVP release from CP epithelium, and 3) the nature of this secretory process (via either the regulated or constitutive pathway). We will approach the above questions by applying both in vivo rat model and in vitro CP epithelial cell cultures. The functional experiments on AVP release will be complemented with molecular and immuno-chemical analyses, such as reverse transcriptase- polymerase chain reaction, Western blotting, and immuno- cytochemistry. Radioimmunoassay will be used to quantify AVP content. The long-term objective is to obtain a comprehensive view of how the CP-CSF system regulates the internal milieu for neuronal and glial cells. These studies will form the basis for development of pathological models and, consequently, effective therapies for the treatment of CNS disorders, such as trauma, SAH, and stroke.