实验性低氧性肺动脉高压(猪)模型的血浆中血栓素A_2,前列环素和5-羟色胺的变化

The changes in plasma TXA_2, PGI_2 and 5-HT levels in experimental hypoxic pulmonary hypertension

本文报告九只猪在实验性低氧性肺动脉高压时,动静脉中的血栓素A_2的稳定代谢产物血栓素B_2(TXB_2),前列环素的稳定代谢产物6-酮-前列腺素F_(1α)(6-Keto-PGF_(1α))和5-羟色胺(5HT)的变化。结果发现在低氧前后及低氧加克甫定(硫甲丙脯酸,captopril)注射时,动脉血中TXB_2/PGF_(1α)比例显著升高(P<0.01),动脉中的5HT亦升高(P<0.05)。提示TXA_2/PGI_2的比例升高可能对低氧肺动脉高压有一定的作用。

The effcct of vasoactive substances on acute hypoxic pulmonary hypcrtension has not been established yet. To exposc the relationship of TXA_2/PGI_2, 5-HT in hypoxic induced pulmonary hypertension, nine pigs were studied before and after hypoxic ventilation and hypoxic with Captopril injection (7.3mg/kg iv over six minutes). Swan Ganz cathetcr and arterial catheter were inserted respectively into the pulmonary artery and aorta for monitoring the pulmonary artery pressure (PAP), cardiac output(CO) pulmonary capillary wedge pressure (PCWP) and systematic blood pressure. Arterial gases, plasma TXB_2 and 6-keto-pGF_(1α) (the stable mctabolitcs of TXA_2 and PGI_2) were estimated using radioimmunoassary 5-HT assayed by fluorencence method. It was found that after hypoxemia (PaO_2 6.30±0.3 kPa PaCO_2 5.4±0.2 kPa) PAP rose from 2.43±0.17 to 3.80±0.30 kPa.(P<0.05). At the same time TXB_2 increased from 120±18.5 to 392.6±78.9 ng/L,(P<0.05)6-keto-PGF_(1α) decreased from 142.5±18.8 to 113.1±19.1ng/L, (P<0.05) in arterial blood. The ratio of TXB_2/6-keto-pGF_(1α) also significantly increased from 0.84 to 3.40, (P<0.01) as compared with normal ventilation. Meanwhile 5-HT increased significantly in arterial blood (P<0.05). It is supposed that an increased ratio of TXB_2/6-keto-pGF_(1α) may be one of the factors cousing vasoconstricton.