短期缺氧-复氧对大鼠血管平滑肌细胞myocardin基因表达的影响

目的 研究短期缺氧-复氧对大鼠血管平滑肌细胞myocardin基因表达的影响.方法 无菌条件下留取大鼠胸主动脉中膜,采用组织贴块法培养的第4～7代细胞,通过观察细胞在缺氧环境下形态学变化、死亡细胞计数等,判断缺氧刺激对体外培养平滑肌细胞活性的影响,并与正常培养箱内对照进行比较.提取细胞总RNA,用RT-PCR法,研究平滑肌细胞在缺氧及复氧后不同时间段myocardin mRNA的表达变化.结果培养细胞呈典型的"峰谷"样生长.自制缺氧装置24 h内氧分压明显降低,且pH值波动不明显.RT-PCR结果表明,与正常对照组相比,平滑肌细胞myocardin mRNA表达在缺氧12、24 h后逐渐降低[(0.871±0.053)与(0.573±0.074)、(1.329±0.042),P＜0.05].缺氧12 h降低最明显.且随着缺氧时间的延长,myocardin基因的表达水平逐渐回升,并增高;缺氧24 h再复氧6 h后,其表达水平逐渐回升,复氧12 h接近正常表达水平.结论 短期缺氧-复氧影响大鼠血管平滑肌细胞myocardin基因的表达.

Effects of hypoxia-reoxygenation on the expression of myodardin gene in vascular smooth muscle cells

Objective To investigate the influence of hypoxia-reoxygenation on the myocardin gene expression of cultured rats' vascular smooth muscle cells(SMC).Methods The SMC were isolated from the media of the thoracic aorta vessel of Sprague-Dawley rats,and cultured with attachment-block manner.The morphology and cell counting of the cultured cells under hypoxia conditions were observed and comparedto that under normal culture condition.Total RNA extracted from the cultured cells,the expression of myocardin mRNA in SMC were measured at hypoxia status and at various time after reoxygenation through RT-PCR.Results The rats' vessel SMC was successfully cultured and showed a "peak-valley" shape.Self-made hypoxia equipment can produce a lower oxygen partial pressure without significant variation of pH value which met the experiment requirements in 2 4 hours .However,in the hypoxia conditions,the expression level of myocardin was lowest at the 12th hours,then increased.After 24 hours of hypoxia,the expression levels of myocardin began to increase at the 6th hour of reoxygenation and reached a normal level at the 12th hour of reoxygenation.Conclusions Hypoxia-reoxygenation has an effect on the expression of myodardin gene.