Active control of endothelial cell functions by the microblood flow

动脉血管内表面的内皮细胞在微观上受外界机械刺激而具有分泌、摄取等多种功能。因此，本文研究了用激光共聚焦显微镜观察内皮细胞的微血流和大分子摄取，并揭示了微血流和大分子摄取之间的关系。本研究采用猪主动脉血管内皮细胞。在剪切应力下暴露48小时后，盖片上的内皮细胞层在含有异硫氰酸四甲基罗丹明结合白蛋白（tritc -白蛋白）的PBS中于37℃孵育60分钟。然后，通过细胞间区观察白蛋白的摄取和内皮细胞的形状。白蛋白的摄取取决于施加的剪切应力。在10 dyn/cm2时，白蛋白摄取增加1.3倍。白蛋白吸收量随剪切应力的增加而减少，最小吸收量为控制值的四分之一，为60 dyn/cm2。这种剪切依赖性摄取是细胞的独特特征，可能在内皮细胞的控制机制中起关键作用。

The endothlial cells on the inner surface of arterial vessel have various functions such as the secretion and uptake due to the external mechanical stimulus in the microscopic level. So the present study dealt with the microblood flow and the uptake of macromolecules in the endothelial cells which were obserced by the confocal laser microscopy and the corelation between the microblood flow and the uptake of macromolecules is to be revealed. In this study the endothelial cells obtained from the aortic vessel of pig is employed. After 48 hour exposure to shear stress, the endothelial cell layr on coverslips were incubated at 37C for 60 minutes in PBS containing tetramethylrhodamine isothiocyanate conjugate albumin (TRITC-albumin). Thereafter the uptake of albumin and the shape of endothelial cells were observed by a intercellular region. The albumin uptake depends on imposed shear stress. At 10 dyn/cm2, the albumin uptake showed a 1.3 folds increase. The albumin uptake decrease with increasing shear stress and the minimum uptake is quater of the control value at 60 dyn/cm2. This shear dependence of uptake is an unique feature of the cell and may play a key role for the controlling mchanism of endothelial cells.