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目的 探讨流体剪应力(fluid shear stress,FSS)对VWF-A1 A2A3介导的血小板表面P-选择素表达的影响.方法 利用平行平板流动腔实验系统,以CD62P:FITC作为血小板表面P-选择素表达的指示剂,采用荧光显微镜观察分析在不同FSS条件(0、1、2 Pa)下,血小板经由VWF-A1A2A3特异介导黏附后P-选择素表达随时间的变化过程,提取特征参数.结果 FSS扣动了血小板激活并产生P-选择素表达的扳机,激活比率受FSS大小和持续时间的正向调节,在1 Pa和2 Pa时的最高激活比率分别为9.42％和14.59％;P-选择素表达水平随FSS作用时间的延长先提高后降低,呈现一个“双相”的变化过程,最佳作用时间为7.5 min;P-选择素表达的荧光峰值随剪应力的增加而上升.结论 血小板P-选择素表达受FSS和VWF-A1 A2A3的协同调控,表达水平与力信号的持续时间相关.“,”Objective To investigate the effect of fluid shear stress (FSS) on VWF-A1A2A3-mediated expression of platelet surface P-selectin.Methods Using a parallel plate flow chamber system and mouse anti-human CD62P:FITC as the indicator of P-selectin expression,the alteration of platelet P-selectin expression level with increasing exposure time under different FSS conditions (0,1,2 Pa) specifically mediated by VWF-A1A2A3 was observed and analyzed by fluorescence microscope to obtain the activation characteristics.Results FSS triggered platelet activation and P-selectin expression.The activation ratio of platelet was positively regulated by FSS and their exposure time,reaching the maximum value,9.42％ and 14.59％ under FSS of 1 Pa and 2 Pa,respectively.The level of P-selectin expression exhibited two-phase tendency with the shear stress-exposure time increasing,uplifted at first,then decreased,with the best action time at 7.5 min.The fluorescence peak intensity increased when FSS was enhanced.Conclusions The level of platelet P-selectin expression is co-regulated by VWF-A1A2A3 and FSS,and is closely related to force-signaling exposure time.