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

设计了单细胞对机械应力响应的分析系统，并利用该系统测定了动、静脉内皮细胞和血管平滑肌细胞的负荷-伸长关系。该系统由倒置显微镜、共焦激光扫描仪、微操作器、压电式和直驱式直线驱动器、激光位移计、视频尺寸分析仪(VDA)、个人计算机和恒温试验室组成。试验室和显微镜安装在隔振器上。细胞用一对微吸管在其细小的尖端用聚亚安酯树脂夹持。其中一根微吸管固定在悬臂上，另一根固定在用于拉伸细胞的线性执行器上。用激光位移计测量悬臂梁的挠度，并换算成载荷。2.大鼠颈总动脉和颈静脉内皮细胞的硬度分别为0.042 N/m和0.032 N/m。3.兔胸主动脉内皮细胞收缩细胞的硬度为0.89N/m，松弛细胞的硬度为0.14N/m。4.利用该系统分别观察了血管平滑肌细胞和血管内皮细胞内肌动蛋白细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.