CHARACTERIZATION OF MAST CELL HISTAMINE

肥大细胞组胺的表征

• 批准号: 3137038
• 负责人: DALLAS Leroy RABENSTEIN
• 金额: $ 10.82万
• 依托单位: UNIVERSITY OF CALIFORNIA RIVERSIDE
• 依托单位国家: 美国
• 财政年份: 1987
• 资助国家: 美国
• 起止时间: 1987-07-01 至 1990-06-30
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/3137038
• 关键词: acidity /alkalinity; chemical binding; exocytosis; heparin; histamine; histamine release; intracellular; laboratory rat; mast cell; mucopolysaccharides; nuclear magnetic resonance spectroscopy; potassium; secretion; sodium; water

Mast cells and their homologues, the basophil and the mucosal mast cell, are the primary effector cell type in a range of inflammatory reactions, such as hayfever and asthma. When stimulated by cross-linking of surface bound immunoglobulin E, mast cells release performed histamine from membrane-enclosed, cytoplasmic granules. Despite the importance of the storage of histamine in the secretory granules, little is known at the molecular level about the intragranular state of histamine or the nature of the intragranular environment. This is due in part to the lack of tools with which intact cells can be examined at the molecular level. It is the aim of this research (1) to characterize the intragranular environment of mast cell secretory granules with respect to pH, water content and the mobility of intragranular histamine, (2) to identify the changes in granules with respect to pH and histamine mobility that occur prior to extrusion of the granule during exocytosis, and (3) to fully characterize the binding of histamine by granules in terms of affinity constants and binding sites. These objectives will be accomplished by using noninvasive 1H nuclear magnetic resonance (NMR) spectroscopy to examine histamine in intact mast cells and in histamine-granule and histamine-glycosaminoglycan model systems. The mobility of histamine in intact cells, in mast cells which have been arrested following stimulation, and in granules will be determined from relaxation times for histamine protons. Affinity constants for the binding of histamine by granules and glycosaminoglycans will be determined from chemical shift and intensity measurements. Intragranular pH will be determined by using added imidazole as an NMR pH indicator, while a small, neutral, granule permeable molecule, such as methanol, will be used as a reporter of water volume. It is anticipated that these studies will contribute to an increased comprehension of mast cell behavior which is essential for deliberate perturbation of the secretory process for therapeutic purposes.

肥大细胞及其同系物、嗜碱性粒细胞和粘膜细胞 肥大细胞是一系列细胞中的主要效应细胞类型 炎症反应，例如花粉热和哮喘。 什么时候 通过表面结合免疫球蛋白 E 的交联刺激， 肥大细胞从膜封闭中释放组胺， 细胞质颗粒。 尽管存储很重要 分泌颗粒中的组胺，目前知之甚少 组胺或颗粒内状态的分子水平 粒内环境的性质。 这部分是由于 缺乏可以在实验室检查完整细胞的工具 分子水平。 本研究的目的 (1) 表征 肥大细胞分泌颗粒的颗粒内环境 关于pH值、水含量和流动性 颗粒内组胺，（2）识别颗粒的变化 关于发生在之前的 pH 值和组胺迁移率 胞吐作用期间颗粒的挤出，以及（3）充分 描述颗粒与组胺的结合的特征 亲和常数和结合位点。 这些目标将是 通过使用无创 1H 核磁共振来完成 (NMR) 光谱法检查完整肥大细胞中的组胺和 在组胺颗粒和组胺糖胺聚糖模型中 系统。 组胺在完整细胞和肥大细胞中的流动性 在刺激后被捕获，并以颗粒形式存在 将由组胺质子的弛豫时间确定。 颗粒与组胺结合的亲和力常数 糖胺聚糖将通过化学位移确定 强度测量。 颗粒内 pH 值由下式确定 使用添加的咪唑作为 NMR pH 指示剂，同时小的， 中性、颗粒可渗透的分子，例如甲醇，将 用作水量的报告者。 预计这些 研究将有助于增进对肥大细胞的理解 故意扰乱环境所必需的行为 用于治疗目的的分泌过程。