VASCULAR CELL INTERACTIONS AND FLOW IN VIVO

本项目的重点是终末微血管网络在 确定血细胞(红细胞、红细胞和 白细胞)和在确定血流分布方面的作用 微血管系统。我们认为血液流动和血细胞的异质性 作为局部生物物理现象的可预测结果的行为及其 生物学结果。AIM 1基因以RBC决定因素为中心 分发。AIM 1.1测试了RBC分布到 流经时，毛细血管是红细胞表面积与体积比的函数。 在项目3中，将确定经修改的RBCs的流动特性 急性和慢性的毛细血管；细胞的机械性能 体外测量的红细胞流量、流速和毛细血管几何形状 活着。Aim 1.2测试分支几何对 对红细胞分布的不对称性，使用红细胞悬浮液灌流 通过模拟末梢小动脉的微通道系统 分叉几何。《将军2》探讨了 内皮细胞(EC)细胞骨架重排与流动，以及几何结构 (曲率)的EC生长表面。Aim 2.1测试了以下假设 内皮细胞对血流的细胞骨架反应在不同生长的细胞中不同。 与平面相比是弯曲的。F-肌动蛋白分布将在 不同来源的ECs在不同的流量和曲率下生长。焦点 还将测量附着力分布。Aim 2.2验证了该假设 活体内皮细胞可以通过细胞骨架对血流变化做出反应 重新调整。局部微动脉灌流将用于混合 血管活性物质不同流向下的微血管和F-肌动蛋白染色 刺激物。第3代AIM阐述了WBC-EC的潜在机制 活体内的相互作用。Aim 3.1测试了以下假设： WBC在小静脉中的分布是由于WBC的首选流动通道所致。 WBC血流参数将与静脉曲张相关 结构，在不同的流动，或没有选定的黏附分子。 黏附分子的局部静脉异质性将从 P-选择素和ICAM-1的分布，以及用停用的白细胞 由Project 1开发的时间分析。Aim 3.2测试他们的假设 EC-WBC的相互作用可以由于EC中与流动相关的变化而改变。 在项目2中，我们将在活体内测量EC体积变化和WBC流量 组织缺血前后应用阿米洛利预防EC 改变。在微通道中，我们将探索EC潜在机制 流量的体积响应，以及对WBC-EC相互作用的影响。

This project focuses on the role of the terminal microvascular network in determining the variable behavior of blood cells (erythrocytes, RBC and leukocytes, WBC) and in determining blood flow distributions in the microvasculature. We view the heterogeneity in blood flow and blood cell behavior as a predictable result of local biophysical phenomena and their biological outcomes. Gen. Aim 1 centers on determinants of RBC distribution. Aim 1.1 tests the hypothesis that RBC distribution into, and flow through, capillaries is a function of RBC surface to volume ration. With Project 3, flow properties of modified RBCs will be determined in capillaries both acute and chronically; cell mechanical properties will be measured in vitro and RBC flux and velocity and capillary geometry in vivo. Aim 1.2 tests the hypothesis that bifurcation geometry contributes to asymmetries in distribution of RBCs, using RBC suspensions perfused through microchannel systems constructed to mimic terminal arteriolar bifurcation geometry. Gen. Aim 2 explores the relationship between endothelial cell (EC) cytoskeletal realignment with flow, and the geometry (curvature) of the EC growth surface. Aim 2.1 tests the hypothesis that the cytoskeletal responses of ECs to flow is different in cells growing on curved compared to flat surfaces. F-actin distribution will be measured in ECs of different origins grown under varying flow and curvature. Focal adhesion distribution will also be measured. Aim 2.2 tests the hypothesis that ECs in vivo can respond to flow changes with cytoskeletal realignment. Local perfusion of arterioles will be used to mix microvessels and stain F-actin, under differing flow of vasoactive stimuli. Gen. Aim 3 addresses the mechanisms underlying WBC-EC interactions in vivo. Aim 3.1 tests the hypothesis that heterogeneity in WBC distribution among venules is due to preferred flow channels for WBCs. WBC flow variables will be quantitated in related to the venular architecture, at differing flows, or without selected adhesion molecules. Local venular heterogeneity in adhesion molecules will be quantitated from the distribution of P-selectin and ICAM-1, and also by using a WBC stopped time analysis developed by Project 1. Aim 3.2 tests they hypothesis that EC-WBC interactions can be changed due to flow related changes in ECs. With Project 2 we will measure EC volume changes and WBC flows in vivo before and after tissue ischemia, and with amiloride to prevent EC changes. In microchannels we will explore that mechanism underlying the EC volume response to flow, and effects on WBC-EC interactions.