急性缺氧对肺动脉内皮细胞血栓素合酶基因表达及PGI_2、TXA_2代谢产物的影响

Changes of Thromboxane Synthase Gene Expression, PGI_2 and TXA_2 Production in Response to Acute Hypoxia in Pulmonary Artery Endothelial Cell

为进一步研究 PGI2 和 TXA2 在慢性缺氧性肺动脉高压和机体对慢性缺氧习服过程中的作用 ,动态观察了慢性缺氧进程中肺动脉内皮细胞 (PAEC)血栓素合酶 (TXS)基因表达及 PGI2 、TXA2 代谢产物的变化。结果显示 :常氧培养的 PAEC,急性缺氧后 TXS、 6 -酮 - PGF1α、TXB2 均增加 ,以 6 -酮 - PGF1α增加更明显 ,TXA2 / PGI2 比值降低 ;慢性缺氧 [PO2 (5 .3± 0 .7) k Pa]培养的 PAEC TXS、 6 -酮 - PGF1α、TXB2 均高于同代常氧组 ,复氧再急性缺氧 ,6 -酮 - PGF1α在第 2、 4代减少 ,第 6代不变 ,TXS、TXB2 在第 4代增加 ,第 6代减少 ;TXA2 / PGI2 在第 2、 4代增加 ,第 6代减少。提示在慢性缺氧的不同阶段 ,由急性缺氧所致 TXS、 6 -酮 - PGF1α、 TXB2 及 TXA2 / PGI2

To investigate the role of PGI 2 and TXA 2 in chronic hypoxic pulmonary hypertension and acclimatization to chronic hypoxia, the change of thromboxane synthase (TXS) expression and 6 keto PGF 1α and TXB 2 production in pulmonary artery endothelial cells were measured. Results showed that the expression of TXS mRNA and production of TXB 2 especially 6 keto PGF 1α were increased in acute hypoxia in the PAEC cultured in normoxic condition. The levels of TXS mRNA, 6 keto PGF 1α and TXB 2 were higher in chronic hypoxic group than in the corresponding normoxic group. After exposure to acute hypoxia, the level of 6 keto PGF 1α was decreased significantly in the 2nd and 4th subculture and were not changed in the 6th subculture, while the level of TXS mRNA and TXB 2 in creased in the 4th subculture and decreased in the 6th subculture. The ratio of TXA 2 to PGI 2 was decreased in NH group while increased in HH group by acute hypoxia in 2nd and 4th subcultures. In the 6th subculture, the ratio was not changed in NH group while decreased in HH group. It was suggested that the changes of TXS mRNA, PGI 2 and TXA 2 by acute hypoxia were different between chronic hypoxia group and normoxic group.