SHEAR STRESS ENHANCED SOLUTE TRANSPORT ACROSS MEMBRANES

剪切应力增强溶质跨膜运输

• 批准号: 3467376
• 负责人: TODD D GIORGIO
• 金额: $ 9.92万
• 依托单位: VANDERBILT UNIVERSITY
• 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/3467376
• 关键词: acidity /alkalinity; adenine nucleotides; animal tissue; biological fluid transport; body fluid viscosity; calcium channel blockers; calcium flux; cell membrane; cytolysis; diffusion; fluorescence spectrometry; granule; homeostasis; ion transport; liposomes; luciferin; luciferin monooxygenase; mathematical model; membrane model; membrane permeability; membrane potentials; membrane proteins; model design /development; nonblood rheology; pharmacokinetics; platelet activation; platelet aggregation; platelets; prostaglandins; tissue /cell culture; vascular endothelium

The proposed research plan is focused on the study of calcium ion influx through cellular membranes as a function of fluid shear stress. Blood platelets and endothelial cells will be studied independently to determine the impact of shear stress-enhanced transmembrane calcium ion flux on intracellular free calcium ion concentration. The effect of shear stress on the diffusional and convective transport of other biologically important substances will also be examined. Insight into the initiating steps of fluid mechanical cellular activation will be sought. The influence of elongational stress on fluid dynamic platelet activation will be evaluated. Measurements will be made continuously with a cone and plate viscometer, a parallel plate flow chamber or an 'elongational flow rheometer'. each modified for fluorescence and luminescence measurement. Intracellular calcium ion concentration, intracellular pH, membrane potential and platelet dense granule release will be monitored continuously during fluid stress exposure. The rotational chamber geometry permits application of a unifom, well-described shear field to the entire sample volume. The parallel plate apparatus can apply well-described shear stress to anchorage-dependent cells attached to one wall of the flow chamber. The 'elongational flow rheometer' produces a flow of uniform, constant acceleration which results in the application of a constant fluid dynamic stretching force. Proposed studies will utilize unilamellar liposomes as model cell membranes. Use of liposomes will decouple the calcium ion flux measurement in a clear and unambiguous way from the normal cellular processes of calcium ion homeostasis. Tbe role of platelet membrane proteins in the management of calcium ion flux will be investigated through preparation of liposomes from isolated platelet membranes. Tbe effect of cardiovascular fluid stress on the efflux kinetics of pharmaceuticals from liposomes will also be studied. The results obtained from experiment will be incorporated into a mathematical model of shear stress enhanced transport through cell membranes. A predictive scheme will be developed to estimate the degree of shear stress induced transport as a function of physical system parameters and fluid dynamic exposure.

拟议的研究计划的重点是钙离子涌入的研究 通过细胞膜作为流体剪应力的函数。 血 血小板和内皮细胞将被独立研究 确定剪切应力增强的跨膜钙离子的影响 细胞内无钙离子浓度上的通量。 效果 对其他的扩散和对流运输的剪切应力 还将检查生物学上重要的物质。 深入了解 流体机械细胞激活的启动步骤将是 寻求。 伸长应力对流体动态血小板的影响 将评估激活。 测量将用锥和板粘度连续进行， 平行板流室或“延长流变仪”。每个 修改了荧光和发光测量。 细胞内 钙离子浓度，细胞内pH，膜电位和 血小板致密的颗粒释放将在 流体应力暴露。 旋转室几何允许 在整个样品中应用一个单体，描述的剪切场 体积。 平行板设备可以施加良好的剪切 与锚定依赖性细胞的压力，附着在流动的一壁上 腔室。 “延长流变仪”产生统一流动的流动 恒定加速度导致应用常数 流体动态拉伸力。 拟议的研究将利用单层脂质体作为模型细胞 膜。 脂质体的使用将使钙离子通量脱离 从正常细胞以清晰而明确的方式进行测量 钙离子稳态的过程。 血小板膜的作用 将研究钙离子通量管理中的蛋白质 通过从分离的血小板膜上制备脂质体。 TBE 心血管液应力对外排动力学的影响 还将研究来自脂质体的药物。 从实验获得的结果将被纳入 剪切应力的数学模型增强了通过细胞的传输 膜。 将制定一个预测方案以估计程度 剪切应力诱导的转运与物理系统的关系 参数和流体动态暴露。