SEROTONIN (5-HT) RECEPTORS AND SALIVARY GLAND FUNCTION

描述（改编自研究者摘要）：生物胺， 血清素（5-羟色胺，[5-HT]）是一种重要的细胞外调节剂 在中枢神经系统和许多外周组织中， 胃肠道、泌尿道、肾上腺皮质和脉管系统。 主要研究者实验室发布的数据表明 在完整灌注的大鼠下颌下腺中，5-HT减少， 乙酰胆碱诱导的唾液流和增加唾液蛋白质含量。5-HT 还增加分散的SMG中的cAMP产生（以及舌下和 腮腺）细胞聚集，但对SMG细胞内游离Ca 2+无影响 浓度的本提案中提供的数据表明，大鼠SMG 共表达两种5-HT受体亚型，5-HT 4 b和5-HT 7，两者都是 与cAMP的产生正相关。这一提议的主要假设是 cAMP偶联的5-HT受体在大鼠SMG中发挥生理作用， 调节腺体功能。这种受体可能是潜在的治疗药物 影响唾液腺功能的疾病中的靶点。的目标 研究内容为：1.明确大鼠SMG中5-HT受体的组成 根据亚型和使用分子的每个亚型的受体密度， 药理学和放射性配体结合技术。2.确定 5-HT受体亚型的细胞类型特异性分布 来自SMG的分散的导管和腺泡富集的细胞聚集体中的测定， 结合原位杂交研究，旨在共同定位5-HT 受体亚型mRNA与细胞类型特异性标记蛋白质， 荧光技术，3.为了验证腺苷酸环化酶-cAMP-cAMP 依赖性蛋白激酶信号通路介导5-HT在 SMG，通过使用选择性药理学工具， 该途径与亚型特异性5-HTR配体结合;和4.到 开始评估SMG 5-HT受体的生理相关性， 确定腺体中的5-HT水平，检测关键的5-HT合成 SMG中的酶并测定高亲和力5-HT的存在和水平 转运蛋白（SERT）在SMG。成功实现这些目标将有助于 解决5-HT是否是不断增长的代理人名单之一的问题 参与哺乳动物唾液腺功能的调节， 刺激对5-HT受体作为治疗靶点的兴趣， 唾液腺功能障碍

DESCRIPTION (adapted from the Investigator's abstract): The biogenic amine, serotonin (5-hydroxytrptamine, [5-HT]) is an important extracellular regulator in the central nervous system and many peripheral tissues including the gastrointestinal tract, urinary tract, adrenal cortex, and vasculature. Published data from the Principal Investigator's laboratory have demonstrated that, in the intact perfused rat submandibular gland, 5-HT decreases acetylcholine-induced saliva flow and increases saliva protein content. 5-HT also increases cAMP production in dispersed SMG (as well as sublingual and parotid) cell aggregates, but has no effect on SMG cell intracellular free Ca2+ concentrations. The data presented in this proposal suggest that rat SMG co-expresses two 5-HT receptor subtypes, 5-HT4b and 5-HT7, both of which are positively coupled to cAMP production. The main hypothesis of this proposal is that cAMP-coupled 5-HT receptors in the rat SMG play physiological roles in the regulation of gland function. Such receptors might be potential therapeutic targets in diseases affecting salivary gland function. The goals of the research are: 1. To define conclusively the 5-HT receptor complement in rat SMG in terms of subtypes and receptor density of each subtype using molecular, pharmacological, and radioligand binding techniques. 2. To determine the cell-type specific distribution of 5-HT receptor subtypes using functional assays in dispersed duct and acinar -enriched cell aggregates from SMG in conjunction with in situ hybridization studies designed to co-localize 5-HT receptor subtype mRNAs with cell-type specific marker proteins using dual fluorescence techniques, 3. To verify that the adenyl cyclase-cAMP-cAMP dependent protein kinase signaling pathway mediates the 5-HT effects in the SMG, through use of selective pharmacological tools which activate or inhibit this pathway in conjunction with subtype-specific 5-HTR ligands; and 4. To begin to assess the physiological relevance of SMG 5-HT receptors by determining the 5-HT levels in the gland, detecting the key 5-HT synthetic enzyme in SMG and determining the presence and level of high affinity 5-HT transporters (SERT) in SMG. Successful completion of these goals will help to resolve the question of whether 5-HT is one of the growing list of agents involved in the regulation of mammalian salivary gland function and might stimulate interest in 5-HT receptors as therapeutic targets in patients with salivary gland dysfunction.