慢性缺氧改变肺内动脉平滑肌细胞环氧合酶基因的表达

目的研究慢性缺氧对肺动脉平滑肌细胞环氧合酶基因表达的影响.方法根据常氧(PaO2152mmHg)及慢性缺氧(PaO240±5nmHg)的不同培养条件,将平滑肌细胞分为常氧组和慢性缺氧组,采用半定量RT-PCR技术检测大鼠肺内动脉平滑肌细胞环氧合酶(COX)基因的表达及其对急性缺氧刺激的反应.结果COX-1mRNA的表达不受缺氧及传代的影响,而COX-2mRNA的表达随慢性缺氧时间延长而增加,在4、6代慢性缺氧培养组均高于同代常氧组水平(P＜0.05).急性缺氧后COX-2mRNA增加的幅度在慢性缺氧组均大于同代常氧组,以第四代最为显著.结论慢性缺氧可增强急性缺氧时肺内动脉平滑肌细胞COX-2基因的表达,在慢性缺氧所致肺血管对缺氧的反应性降低中可能起作用.

Chronic hypoxia altered the mRNA expression of cyclooxygenase in intrapulmonary artery smooth muscle

Objective To elucidate the effect of chronic hypoxia on the cyclooxygenase 2 mRNA expression in pulmonary artery smooth muscle cells of rats. Methods The gene expressions of COX 1 and COX 2 during acute hypoxia were measured with semi quantified RT PCR in the 2nd, 4th and 6th subculture of intrapulmonary artery smooth muscle cells (PASMC) of wistar rats under normoxic and continuous hypoxic condition separately Results In all three generations, the expressions of COX 1 had no significant changes in hypoxia, while the COX 2 mRNA expression was higher in chronic hypoxic group than that in normoxic group and elevated with the duration of hypoxia exposure. After exposure to acute hypoxia, the augmentation of COX 2 mRNA expression in PASMC was higher in chronic hypoxic group than in normoxic group in all three subcultures Conclusion Chronic hypoxia could enhance the mRNA expression of cyclooxygenase 2 caused by acute hypoxia in PASMC of rats It might be responsible for the lower HPV under chronic hypoxia.