机械拉伸对人肺上皮细胞粘附及[Ca2+]i的影响

目的探讨周期性拉伸应变对人肺上皮细胞H727的力学性质及其[Ca2 ]i的调控作用.方法应用微管吸吮系统测定细胞与基底间的粘附力和细胞的铺展面积,用荧光探针Fluo-3/AM测定拉伸应变对人肺上皮细胞H727[Ca2 ]i的影响.结果在应变为15%,频率为40次/min的拉伸刺激下,与其静态对照组相比,细胞与基底间的粘附力和细胞的铺展面积均增加;拉伸5 min后,[Ca2 ]i比对照组有明显增加,用三七总皂苷阻断胞内Ca2 离子通道后,细胞对应变的响应仍表现出[Ca2 ]i的升高,但与未加三七总皂苷的实验组相比,[Ca2 ]i响应应变后的升高由原来的3.4倍的增加降低为1.5倍的增加.结论在人肺上皮细胞H727响应周期性拉伸应变的过程中,[Ca2 ]i的升高既有胞外钙内流的参与,也有胞内钙库的释放作用,其中胞外钙通过跨膜通道的内流起主要作用.

Effects of cyclic mechanical stretch on the adhesion and the intracellular calcium concentration of human pulmonary epithelial cells

Objective To study regulatory effect of cyclic mechanical cyclic stretch on the adhesion and the intracellular calcium concentration of human pulmonary epithelial cells. Methods The micropipette aspiration was used to study the effect of cyclic stretch on the mechanical property of human pulmonary epithelial H727 cells. The fluorescence probe Fluo 3/AM was used to investigate the changes of intracellular calcium concentration when human pulmonary epithelial cells responded to the stretch. Results The cyclic stretch increased the adhesion force, spreading areas, and the intracellular calcium concentration of human pulmonary epithelial cells. Conclusion The rise of intracellular calcium concentration is resulted from the influx of extracellular calcium and the release of intracellular calcium store, in which the influx of extracellular calcium plays the main role.