Development of a system for the analysis of the response of a single cell to mechanical stress

设计了一种分析单个细胞对机械应力响应的系统，并利用该系统确定了动脉、静脉内皮细胞和血管平滑肌细胞的载荷-伸长关系。该系统由配备共聚焦激光扫描仪的倒置显微镜、微操纵仪、压电和直接驱动线性执行器、激光位移计、视频尺寸分析仪（VDA）、个人计算机和恒温测试室组成。试验箱和显微镜安装在隔振器上。一个细胞被一对微移液管抓住，在它们的尖端使用聚氨酯树脂。其中一个微移液管固定在悬臂上；另一个连接到用于拉伸单元的线性执行器上。用激光位移计测量悬臂梁的挠度，并将其转化为载荷。伸长是由用VDA.2测量的微移液器尖端之间的距离确定的。2 .大鼠颈总动脉和颈静脉血管内皮细胞的硬度分别为0.042 N/m和0.032 N/m。兔胸主动脉平滑肌细胞收缩时的刚度为0.89 N/m，松弛时的刚度为0.14 N/m。在血管平滑肌细胞和血管内皮细胞中分别观察到肌动蛋白丝的三维分布和细胞内钙离子浓度的变化。

A system for the analysis of the response of a single cell to mechanical stress has been designed, and the load- elongation relationships of arterial and venous endothelial cells and vascular smooth muscle cells have been determined with this system.1. The system consists of an inverted microscope equipped with a confocal laser scanner, micromanipulalois, a piezo and a direct drive linear actuators, a laser displacement meter, a video dimension analyzer (VDA), personal computer, and a thermostatic test chamber. The test chamber and the microscope are mounted on a vibration isolator. A cell is gripped with a pair, of micropipettes at their fine tips using a polyurethane resin. One of the micropipettes is fixed to a cantilever ; the other one is attached to the linear actuator which is used to stretch the cell. Deflection of the cantilever is measured with the laser displacement meter, and converted into load. Elongation is determined from the distance between the micropipette tips measured with the VDA.2.The stiffness of the arterial and venous endothelial cells harvested from the rat common carotid artery and jugular vein, respectively, was 0.042 N/m and 0.032 N/m, respectively.3.The stiffness of the smooth muscle cells harvested from the rabbit thoracic aorta was 0.89 N/m in contractedcells and 0.14 N/m in relaxed cells.4.Three-dimensional distribution of actin filaments and change in intracellular calcium ion concentration were observed in vascular smooth muscle cells and vascular endothelial cells, respectively, with this system.