中文摘要：

目的研究细胞密度对体外培养兔关节软骨细胞糖胺多糖（glycosamino—ycan，GAG）合成的影响。方法1月龄新西兰兔5只，无菌手术切取双膝关节软骨，采用0．4％Pronase酶和0．025％Ⅱ型胶原酶消化分离关节软骨细胞，来源于同-只兔的软骨细胞分为两部分：-部分以密度2×10-^4／cm2接种，传代时仍以相同密度接种；另-部分在细胞贴壁后人工降低细胞密度至2×10-^3／cm2培养。原代（P0）和传1代（P1）细胞均在细胞融合后换液，并且于换液后12，24，36，48，60h分别抽取上清测量GAG浓度。采用重复测量资料的方差分析，比较低密度培养Po组与高密度培养Po组、P1组上清GAG浓度。结果低密度培养P0组上清GAG含量显著低于高密度培养P0组（P〈0．001），且低于体外培养时间略长的高密度培养P1组软骨细胞（P〈0．05）。结论高密度培养更有利于软骨细胞维持表型，是软骨平面培养的较好方式。

英文摘要：

Objective To study the effect of cell density on glycosaminoglycan （GAG） synthesis of in vitro cultured rabbit articular chondrocytes. Methods Chondrocytes were isolated from the knee joints of 5 one-month-old rabbits. In high density group, chondro- cytes were seeded at 2 ×10-^4/cm2 in every passage. In low density group, ehondroeyts were seeded at 2×10-^3/cm2. The morphology of the cells was observed under inverted microscope. After the confluence of cells, the medium was replaced with serum-free medium. The supernatants were sampled at 24,36,48,60 h after changing the medium. And the GAG concentrations of supernatants were measured by precipitation with alcian blue. Results The GAG concentration in the supernatant of high density seeded chondrocytes was higher than that of low density seeded chondrocytes in primary culture （P 〈 0.001 ）. When the high density passage 1 cells reached 100% con- fluency, chondroeytes experienced longer culture time, but the GAG concentration of the supernatant was higher than that of primary low density seeded chondrocytes（ P 〈 O. 05 ）. Conclusion High density culture may enhance the GAG synthesis of in vitro cultured rabbit articular chondrocytes.