周期性单轴压应力对大鼠髁突软骨细胞早期增殖活性的影响

Early effects of the cyclic uniaxial compressive stress on proliferation of rat condylar chondrocytes

目的探讨不同力值、不同时段体外周期性单轴压应力对大鼠髁突软骨细胞早期增殖活性及功能状态的影响。方法分离培养大鼠髁突软骨细胞至第三代,利用四点弯曲细胞力学加载仪进行体外周期性单轴压应力加载,力值为2000和4000μstrain,时间0、15、30、60、120和240min;采用流式细胞计量术和MTT四甲基偶氮唑盐微量酶反应比色法研究大鼠髁突软骨细胞在周期性单轴压应力作用下增殖活性的变化。结果2000μstrain周期性单轴压应力作用120min后,细胞增殖活性逐步增强,SPF增加(P<0.001);4000μstrain周期性单轴压应力作用60min后,髁突软骨细胞SPF出现了一明显下降,相反G2期细胞比例增高(P<0.001);120min后S期、G2细胞比例开始恢复,240min SPF增加(P<0.001)。加力后1、2、3天,实验组细胞的增殖活性与对照组相比无统计学差异。结论2000μstrain周期性单轴压应力刺激能促进大鼠髁突软骨细胞增殖活性逐步增强;而4000μstrain周期性单轴压应力能引起细胞增殖活性早期发生变化,表现为先抑制后促进。两组细胞增殖活性变化均为暂时性、可恢复的。

Objective To investigate the early effects of the cyclic uniaxial compressive stress on proliferation of the rat condylar chondrocytes in vitro, Methods The third - passage condylar chondrocytes of 2 day - old rat was applied compressive stress by a cellular compressive stress device at 2000μ strain and 4000μ strain （0.5Hz frequency） for 0min, 15min, 30min, 60min, 120min, 240min, respectively. The early effects of the cyclic uniaxial compressive stress on the cell proliferation of rat mandibular condylar chondrocytes were examined by flow cytometry and MTT, Results The cell proliferation did not change obviously with 2000~t strain compressive stress loading within 60min, but it was increased with loading times after 120min. With 4000μ strain compressive stress loading, the percentage of S phase cells was decreased and the percentage of the G2 phase cells was increased at 60min, The percentage of the S and G2 phase cells were recovered to normal proportion at 120min and the cell proliferation was increased at 240min. Conclusion Cell proliferation of condylar chondrocyte could be promoted by 2000μ strain after 120min. Under the condition of 4000μ strain compressive stress, the cell proliferation of condylar chondrocyte was inhibited at first 60min and then promoted after 120min.