中性粒细胞激活及其与内皮细胞粘附的关系

Activation of Neutrophil and its Relation to Neutrophil - Endothelial Cell Adherence

本文利用不同浓度的趋化物质N-甲酰甲硫亮氨酰苯丙氨酸(fMLP)处理中性粒细胞,并采用硝基蓝四唑(NBT)还原法检测中性粒细胞激活率,结合流室系统定量地研究了在不同切应力作用下不同激活状态的中性粒细胞与人脐静脉内皮细胞(HUVEC)粘附的关系。通过显微镜观察、计数及统计分析,结果表明:随着fMLP浓度的增加,中性粒细胞激活率显著增加,二者有着明显的量效关系。同时本实验还表明:中性粒细胞经fMLP处理后,与对照组一样,随着切应力增加,中性粒细胞与内皮细胞粘附率按指数曲线下降;中性粒细胞激活率的增加可以引起中性粒细胞-内皮细胞粘附显著增加,当切应力由小变大时,这种作用有减缓的趋势。以上结果揭示:(1)体内血流产生的切应力可能是阻止中性粒细胞—内皮细胞粘附的重要因素,中性粒细胞粘附随切应力增加而减少有利于体内正常血液循环的维持;(2)中性粒细胞激活可以增加其对内皮细胞的粘附,心脑血管疾病过程中,中性粒细胞激活率增加的病理生理意义可能在于其对内皮细胞粘附的增加,从而引发一系列病理过程。

Neutrophil was activated by chemotactic tripeptide N-formyl - methionyl - leucyl -phenylalanine(fMLP) in different concentration. The activation rate was tested by the method of nitroblue tetrazolium(NBT) reduction. Using flow chamber system, we quantitatively studied the adhesive properties of neutrophil to human umbilial vein endothelial cell (HUVEC) under different shear stress. The results showed: (1)With increasing of fMLP concentration, the activation rate of neutrophil increased significantly; (2)With gradually increasing of shear stress, the adhesion rate of neutrophil pretreated with fMLP decreased, and this change was also found in the control group; (3)With increasing of activation rate of neutrophil, the adhesion rate of neutrophil toHUVEC increased, but the adhesion rate had a tendency to decrease when shear stress increased. The results indicated that: (1) Shear stress induced by bloodstream might play an important role in inhibiting neutrophil - endothelial cell adherence in vivo. (2)The enhanced activation of neu-trophil could increase neutrophil - endothelial cell adherence.