DISSIPATION IN RED CELLS AND RED CELL MEMBRANE

提出了一个多方面的研究来测量粘性耗散 红细胞和红细胞膜中的粘度。 此外还 建议研究细胞和膜粘度在控制 膜蛋白的侧向扩散，个体的变形能力 细胞在毛细管流动和本体流变学性质的浓缩 细胞悬液 红细胞和红细胞膜粘性的测量是 通过使用显微操作和微量吸管抽吸完成 技术，以产生明确定义的细胞变形和流动速率 和膜。 这些流动包括：（1）连续的轴对称流动， 膜从球形细胞体到弹性的圆柱形膜 股或"系绳"，（2）由两个融合产生的轴对称流 细胞（注意，这个特殊的实验允许几乎同时 粘度和扩散系数的测量），（3）表面剪切流 通过红细胞从细长形状恢复到 双凹面盘和（4）血红蛋白流在展开过程中产生的 红细胞从小（3 - 4 μ m直径）移液管中排出后。 连续荧光光漂白将用于测量 荧光膜颗粒从细胞扩散时的扩散率 身体到系绳。 两个细胞融合后的扩散率将 通过跟踪荧光标记膜的运动来研究 蛋白质在其中一个细胞的膜上，当它们扩散穿过一个细胞时， 赤道线 最后，膜和细胞粘度在 控制细胞变形能力的基因将通过研究 红细胞通过单个孔的流动，并通过测量体积 微升包装细胞悬浮液的流变学性质 在磁声粘度计中。 从基本的观点来看，膜粘度是一种表现， 膜分子的集体相互作用。 因此，膜的研究 粘度使我们了解膜的结构。 从实际 的观点，在膜表面的粘性耗散影响其 对传染病、免疫反应和溶血反应的反应 现象。 此外，红细胞对快速形状的反应能力 它在循环中的变化受到影响和控制， 膜的粘性。 所有这些因素（膜和 细胞粘度、膜扩散性和细胞变形性）将被 研究了

A multifaceted study is proposed to measure the viscous dissipation (viscosity) in red cells and red cell membrane. In addition, it is proposed to study the role of cell and membrane viscosity in governing the lateral diffusion of membrane proteins, the deformability of individual cells in capillary flow and the bulk rheological properties of concentrated cell suspensions. Measurement of the viscous properties of red cells and red cell membrane is accomplished by using micromanipulation and micropipet aspiration techniques to produce well-defined rates of deformation and flow of cells and membrane. These flows include (1) the continuous, axisymmetric flow of membrane from a spherical cell body to an elastic, cylindrical membrane strand or "tether", (2) the axisymmetric flow produced by the fusion of two cells (note that this particular experiment permits the nearly simultaneous measurement of viscosity and diffusivity), (3) the surface shear flow produced by the recovery of a red cell from an elongated shape to a biconcave disk and (4) the hemoglobin flow produced during the unfolding of a red cell after it is ejected from a small (3-4 Mum diameter) pipet. Continuous fluorescence photobleaching will be used to measure the diffusivity of fluorescent membrane particles as they diffuse from cell body to tether. The diffusivity subsequent to the fusion of two cells will be studied by following the motion of fluorescently tagged membrane proteins in the membrane of one of the cells as they diffuse across an equatorial line. Finally, the role of membrane and cellular viscosity in governing the deformability of cells will be determined by studying the flow of red cells through a single pore and by measuring the bulk rheological properties of microliter quantities of packed cell suspensions in a magneto-acoustic viscometer. From a fundamental viewpoint, membrane viscosity is a manifestation of the collective interaction of membrane molecules. Thus, studies of membrane viscosity give insight into membrane structure. From a practical viewpoint, viscous dissipation in the membrane surface influences its response to infectious disease, immunological reactions and hemolytic phenomena. In addition, the ability of red cell to respond to rapid shape changes as it moves through the circulation is influenced and controlled by the viscous nature of the membrane. All of these factors (membrane and cell viscosity, membrane diffusivity and cell deformability) will be studied.