ARACHIDONATE METABOLISM IN TICK SALIVARY GLANDS

蜱唾液腺中的花生四烯酸代谢

• 批准号: 3146471
• 负责人: JOHN ROBERT SAUER
• 金额: $ 12.08万
• 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 1996-05-31
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/3146471
• 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.

本研究的目的是研究花生四烯酸 代谢物（类二十烷酸）在蜱唾液腺的生理和 它们作为唾液分泌产物的作用是促进蜱虫进食。 类二十烷酸由几种蜱类的唾液腺分泌， 假设通过防止宿主止血来帮助蜱虫进食 反应，并增加宿主血液在蜱进食部位的流动。 初步数据表明，高浓度的花生四烯酸 存在于唾液中的磷脂酰胆碱和磷脂酰乙醇胺 腺A.美国。 因为我们对扣押一事一无所知 和/或唾液腺中花生四烯酸的合成或 在任何蜱虫进食期间唾液腺中的水平， 问题将在A中研究。美国。 在大多数组织中， 类二十烷酸的应用受到其共同前体的可用性的限制， 从膜磷脂中释放的游离花生四烯酸。 我们 建议建立花生四烯酸的细胞器位置，以及如何 游离水平的花生四烯酸从酯化储存中释放出来， 唾液腺的复合脂质。 的活动和控制 磷脂酶A2将被详细研究。 我们将研究激动剂 诱导磷脂酶A2活性增加及其与GTP- 结合蛋白和调节钙，蛋白激酶C和 脂皮质素样分子 唾液腺的能力， 代谢花生四烯酸在体内和体外进行研究。 这些实验将在内布拉斯加州进行， 从俄克拉荷马州运来的提取物。 类二十烷酸将被分离，鉴定， 采用TLC、HPLC、RIA和酶联免疫测定（EIA）进行定量分析。 唾液来自A.将通过刺激蜱分泌 与已知的分泌激动剂一起使用，并分析类花生酸， 涉及平滑肌生物测定和血小板的药理学活性 聚合来 这些实验将在亚利桑那州进行， 在俄克拉荷马州收集的唾液 我们亦会研究 类二十烷酸用作控制或调节分泌的“局部”激素。 这些实验的结果将使我们能够更清楚地了解 花生四烯酸代谢物在蜱虫-宿主界面的重要性 以及这些分子在使蜱虫高效 病原体的载体。