[Chronic hypoxia altered the mRNA expression of cyclooxygenase in intrapulmonary artery smooth muscle cell].

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.