EXTRAHYPOTHALAMIC AVP: SYNTHESIS AND SECRETION

脉络膜丛（CP）是脑脊液（CSF）的主要产生器，产生并向CSF分泌各种神经肽、生长因子和细胞因子。我们的一般工作假设是，CP来源的多肽不仅通过自分泌作用局部调节CP上皮的功能，而且还对脑内靶细胞发挥远端旁分泌作用。由于脑脊液的不断产生和流动，可通过脑脊液通路到达脑远端区域。本应用的重点是精氨酸抗利尿激素（AVP）。csf源性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几种中枢神经系统疾病，包括创伤、蛛网膜下腔出血（SAH）和缺血。然而，脑脊液AVP的来源和AVP释放到脑脊液的调控尚不清楚。我们之前的研究表明CP上皮可能是脑脊液AVP的来源。本提案的具体目的是深入了解1)脉络膜AVP基因表达的调控，2)细胞内介质和神经激素分泌物促进AVP从CP上皮释放，以及3)这种分泌过程的性质（通过调节或组成途径）。我们将通过体内大鼠模型和体外CP上皮细胞培养来解决上述问题。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，免疫印迹和免疫细胞化学。放射免疫分析法将用于定量AVP含量。长期目标是全面了解CP-CSF系统如何调节神经元和胶质细胞的内部环境。这些研究将为病理模型的发展奠定基础，从而为创伤、SAH和中风等中枢神经系统疾病的治疗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.