流体剪切力对大鼠成骨样细胞生成NO的调节作用

机械应力在骨改建中起着重要的作用。本研究试图探讨机械应力刺激调节成骨细胞生理功能过程中一氧化氮 (NO)的作用机制。通过流室系统对体外培养的大鼠成骨样细胞施加 12 dyn/ cm2的流体剪切力 ,采用 NO荧光检测试剂盒检测细胞受力 5、10、15、30、6 0、12 0 min后不同时段的 NO的表达。结果表明 ,大鼠成骨样细胞受力后生成的 NO明显高于空白对照组 (P<0 .0 5 )。受力细胞在受力后 6 0 min内 ,NO的生成在各时段无明显提高 ,但在6 0 m in后开始明显增加 (P<0 .0 5 )。而空白对照组各时段 NO的生成无显著性差异 (P>0 .0 5 )。机械应力作用下 ,成骨样细胞早期释放 NO,可能是骨组织细胞将机械应力刺激转导入细胞 ,促进骨形成的生化信号分子。流体剪切力刺激诱导的反应早期可能是直接通过激活 c NOS的生化通道来实现 ,在后期可能是通过 i NOS的途径

The Effect of Fluid Shear Stress on the NO Synthesis of Rat Osteoblast-like Cells

This study sought to elucidate the function of NO during the signal transduction wherein fluid shear stress regulates the proliferation and differentiation of osteoblast cells. The isolated rat osteoblast-like cells were exposed to fluid shear stress 12 dyn/cm 2 for 5,10,15,30,60 and 120 min respectively with the use of a flow chamber. The NO release was examined. After the exposure to fluid shear stress,the NO synthesis of rat primary osteoblast-like cells increased significantly (P<0.05) when compared with the control. After 60 minutes of exposure,the release of NO began to increase significantly (P<0.05),but no significant increase as such was seen in the control (P>0.05). NO synthesis may be one of the signal transduction pathways which transduce the fluid shear stress into osteoblast cells. In early stage,it may be induced by cNOS and in late stage by iNOS.