Objective; To investigate the expression of hypoxia inducible factor-lot (HIF-lα) and vascular endothelial growth factor ( VEGF) in rat mandibular condylar chondrocytes cultured under hypoxic and normoxia conditions for different time periods. Methods; The condylar chondrocytes were in vitro cultured from SD rats aged 3 weeks. Cobalt chloride (CoCl2) was used as a chemical hypoxia-inducible reagent to mimic hypoxic microenvironment. HIF-lα and VEGF mRNA were detected by real-time PCR at 12, 24 and 48 hours after initiation of hypoxia and normoxia conditions. Results; HIF-la and VEGF mRNA were increased at 12, 24 and 48 h after hypoxia(P <0.05). There were significantly differences of the expressions of HIF-1α(P <0.05 )and VEGF(P <0.05) mRNA between12 and 24 h, 12 h and 48 h, 24 h and 48 h respectively after hypoxia. In hypoxia culture HIF-la mRNA expression was gradually increased. While VEGF mRNA reached peak at 12h, and then decreased, however, it was higher than normoxia condition at all time points. Conclusion: The expressions of HIF-la and VEGF mRNA are up-regulated under early hypoxia in mandibular condylar chondrocytes. HIF-la increases with the time lasting and may play a role in cartilage vascularization and development.%目的:探讨低氧诱导因子-1α(hypoxia inducible factor-1α,HIF-1α)和血管内皮生长因子(vascular endothelial growth factor,VEGF)的表达变化在髁突软骨生长发育中的意义.方法:选用3周龄SD大鼠的髁突软骨进行原代细胞培养,建立二氯化钴( CoCl2)化学低氧的细胞培养模型,RT- PCR检测常氧状态下与低氧后12、24、48 h内大鼠髁突软骨细胞HIF- 1α和VEGF 的mRNA表达.结果:髁突软骨细胞低氧培养后12、24h、48 h时间点HIF-1α和VEGF的mRNA表达均明显升高(P＜0.05)；并且VEGF、HIF-1α表达12h与24h、12 h与48 h、24h与48 h比较差异均有统计学意义；HIF-1α表达逐次升高,而VEGF在12 h达到最高点后逐次下降,但是均高于常氧状态下.结论:低氧早期可上调髁突软骨细胞HIF-1α、VEGF mRNA表达,可能在髁突软骨血管形成及生长发育发挥重要作用.
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