EXTRAHYPOTHALAMIC AVP: SYNTHESIS AND SECRETION

脉络丛是脑脊液的主要来源，可向脑脊液中分泌多种神经肽、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对CP上皮细胞的功能进行局部调节，而且还对大脑中的靶细胞产生远端旁分泌作用。由于脑脊液的持续产生和流动，脑远端区域可能通过脑脊液通路到达。本应用的重点是精氨酸加压素(AVP)。脑脊液携带的AVP在促进脑水肿和血管痉挛方面发挥重要作用，这些疾病伴随着几种中枢神经系统疾病，包括创伤、蛛网膜下腔出血(SAH)和脑缺血。然而，脑脊液中AVP的来源以及AVP释放到脑脊液中的调节机制还不是很清楚。我们以前的研究表明，脑脊液中的脑脊液AVP可能来源于脑脊液中的脑脊液。本研究的具体目的是了解脉络膜AVP基因表达的调控，2)细胞内介质和神经激素促进CP上皮释放AVP，以及3)这种分泌过程的性质(通过调节的或构成的途径)。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-聚合酶链式反应、Western blotting和免疫细胞化学。用放射免疫法测定AVP的含量。长期目标是全面了解CP-CSF系统如何调节神经元和神经胶质细胞的内部环境。这些研究将形成发展病理模型的基础，从而形成治疗中枢神经系统疾病的有效疗法，如创伤、蛛网膜下腔出血和中风。

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.