ARACHIDONATE METABOLISM IN TICK SALIVARY GLANDS

蜱唾液腺中的花生四烯酸代谢

• 批准号: 3146470
• 负责人: JOHN ROBERT SAUER
• 金额: $ 12.44万
• 依托单位: OKLAHOMA STATE UNIVERSITY STILLWATER
• 依托单位国家: 美国
• 财政年份: 1991
• 资助国家: 美国
• 起止时间: 1991-08-01 至 1996-07-31
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/3146470
• 关键词: G protein; Ixodes; calcium; communicable disease transmission; cow; eating; eicosanoid metabolism; enzyme linked immunosorbent assay; fatty acid biosynthesis; gas chromatography; high performance liquid chromatography; host organism interaction; laboratory rabbit; laboratory rat; phospholipase A2; protein kinase C; radioimmunoassay; radiotracer; salivary glands; scintillation counter; secretion; sheep; species difference; thin layer chromatography; ticks

The goal of the proposed research is to investigate arachidonic acid metabolites (eicosanoids) in the physiology of tick salivary glands and their role as salivary secretory products that facilitate tick feeding. Eicosanoids are secreted by the salivary glands of several tick species and are hypothesized to assist in tick feeding by preventing host hemostatic reactions and increase the flow of host blood at the tick feeding site. Preliminary data indicate that high concentrations of arachidonic acid are present in phosphatidylcholine and phosphatidylethanolamine in the salivary glands of A. americanum. Because nothing is known about the sequestration and/or synthesis of arachidonic acid in the salivary glands or changes in levels in the salivary glands during tick feeding in any tick, these questions will be studied in A. americanum. In most tissues, the synthesis of eicosanoids is limited by the availability of their common precursor, free arachidonic acid which is liberated from membrane phospholipids. We propose to establish the organelle locations of arachidonic acid and how the free level of arachidonic acid is liberated from esterified stores in complex lipids of the salivary glands. Activity and control of phospholipase A2 will be studied in detail. We will investigate agonist induced increased in phospholipase A2 activity and its linkage to GTP- binding proteins and modulation by calcium, protein kinase C and lipocortin-like molecules. The ability of the salivary glands to metabolize arachidonic acid both in vivo and in vitro will be studied. These experiments will be performed in Nebraska with salivary gland extracts shipped from Oklahoma. Eicosanoids will be separated, identified, and quantified by TLC, HPLC, RIA and enzyme-linked immunoassay (EIA). Saliva from A. americanum will be collected by stimulating ticks to secrete with known agonists of secretion and analyzed for eicosanoids and pharmacological activity involving smooth muscle bioassays and platelet aggregation. These experiments will be performed in Arizona with tick saliva collected in Oklahoma. We will also study the possibility that eicosanoids serve as "local" hormones to control or modulate secretion. Results of these experiments will enable us to have a clearer picture of the importance of arachidonic acid metabolites at the tick-host interface and the importance of these molecules in enabling ticks to be efficient vectors of pathogens.

拟议研究的目标是研究花生四烯酸。 硬蜱唾液腺和唾液腺生理中的代谢物(二十烷基类) 它们的作用是唾液分泌产物，促进扁虱的进食。 二十烷基类化合物是由几种扁虱的唾液腺分泌的， 假设是通过防止宿主止血来帮助喂养扁虱 反应，并增加宿主血液的流量在扁虱的饲养部位。 初步数据显示，高浓度的花生四烯酸 唾液中存在磷脂酰胆碱和磷脂酰乙醇胺 美洲斑潜蝇的腺体。因为人们对自动减支一无所知 和/或唾液腺中花生四烯酸的合成 在扁虱进食过程中，唾液腺中的水平，这些 问题将在美洲冰草中进行研究。在大多数组织中，合成 二十烷类化合物的数量受到其共同前体的可用性的限制， 从膜磷脂中释放出来的游离花生四烯酸。我们 建议建立花生四烯酸的细胞器位置和如何 花生四烯酸的游离水平是从酯化的仓库中释放出来的 唾液腺的复杂类脂。的活动和控制 磷脂酶A2将被详细研究。我们将调查激动剂 诱导的磷脂酶A2活性升高及其与GTP-2的连锁 结合蛋白与钙、蛋白激酶C和钙的调节 脂皮质素样分子。唾液腺的能力 将研究花生四烯酸在体内和体外的代谢。 这些实验将在内布拉斯加州的唾液腺中进行 从俄克拉荷马州运来的萃取物。二十烷类化合物将被分离，鉴定， 采用薄层扫描法、高效液相色谱法、放射免疫法和酶联免疫测定法对其进行定量。 美洲钩端螺旋体的唾液将通过刺激扁虱分泌来收集 已知的分泌物激动剂，并分析了二十烷类化合物和 涉及平滑肌生物测定和血小板的药理活性 聚合。这些实验将在亚利桑那州用TICK进行 在俄克拉荷马州收集的唾液。我们还将研究是否有可能 二十烷类化合物是控制或调节分泌的“局部”荷尔蒙。 这些实验的结果将使我们能够更清楚地了解 壁虱-宿主界面花生四烯酸代谢产物的重要性 以及这些分子在使扁虱变得高效方面的重要性 病原体的传播媒介。