中文摘要：

目的：传代和压力负荷都是影响软骨细胞表型的因素。单层培养的关节软骨细胞在培养过程中随着传代逐渐失去了典型软骨细胞的形态学特征，变得像成纤维细胞，而且Ⅲ型胶原的分泌减少，失去了软骨细胞特异性，即出现了反分化Ⅲ。Lee MS等发现，某些机械应力可诱导软骨细胞凋亡，改变软骨细胞的新陈代谢，也会导致关节软骨的退变。在适当的应力刺激下，软骨细胞可以通过调节基质代谢来适应压力，但在过度或持续的应力下软骨细胞就可能产生各种病理改变口]。本试验将兔软骨细胞放在静水压力负载装置中培养，并传代，在生理水平的流体静态压力范围内（0．1—15MPa）施加不同大小的循环静水压，以及不同大小的持续静水压，观察其对兔软骨细胞损伤和表型的影响。方法：试验组循环加压组分为0．15MPa、0．5Mpa、1MPa三个小组，对照组为持续加压组（分为0．15MPa，0．5MPa，1MPa三个小组）和常压持续培养组。用酶消化法获取兔关节软骨细胞，在静水压力负载装置中按照上述分组作普通培养瓶贴壁的单层培养，并传代。检测Ⅰ型胶原和Ⅱ型胶原免疫组化，苏木素套核染色，倒置显微镜观察摄影。以RT—PCR方法检测软骨细胞中Proteoglycan，Aggrecan，Ⅰ型胶原和Ⅱ型胶原mRNA的表达。结果：在循环静水压力下培养，软骨细胞有较高的细胞增殖率，Ⅱ型胶原，Proteoglycan和Aggrecan等表达增加。生理水平的循环静水压越高，软骨细胞表型越稳定。常压持续培养在第6代开始出现表型改变；持续静水压力培养的软骨细胞更早失去软骨细胞的特有表型，并且持续静水压力越大，表型改变越早。结论：在生理水平的静水压范围内一定频率和大小的循环静水压力能维持或促进软骨细胞的合成分泌功能，有助于软骨细胞特有表型的稳定。

英文摘要：

Objective： To investigate how the chondrocytes phenotype is affected hy different cyclic hydrostatic pressure. Methods： solated rabbit chondrocytes by protease digestion were cultured in monolayer and propagated, group A is under cyclic hydrostatic pressure （0.15MPa,0.5Mpa and 1MPa）contrasted with group B under sustained hydrostatic pressure （0. 15MPa,0.5Mpa, 1MPa and normal pressure）. The proliferation and the intracellular matrix of chondrocytes were observed under light microscopy. The expression of aggrecan, proteoglycan, collagen type I and II were detected with reverse transcription--polymerase chain reaction. Results： Under the cyclic hydrostatic pressure culture, the growth rate was higher than under the sustained hydrostatic pressure. Under the cyclic hydrostatic pressure, the chondrocytes did not change phenotype at the 7th passage. Under the normal pressure, the chondrocytes changed phenotype gradually after the 6th passage. Under the sustained hydrostatic pressure, the chondrocytes changed phenotype earlier. Conclusions： Proper cyclic hydrostatic pressure system is beneficial to the maintenance of the chondrocytes phenotype.