中文摘要：

目的探讨慢性低氧对大鼠血流动力学的影响。方法20只SD大鼠随机分为空白对照组（n=10）和慢性低氧组（rt,=10），空白对照组饲养于海拔2260m处，慢性低氧组饲养于低压氧舱（模拟海拔5000m），均饲养30d。各组行开胸术监测中心静脉压（central venous pressure，CVP）、系统动脉压（system arterial pressure，Psa）、肺动脉压（pulmonary artery pressure，PAP）、主动脉血流量（aortic blood flow，BAF）和左心房压（1eftatrialpressure，Pla）等血流动力学指标后给予低氧通气（17％，5min），观察空白对照组、慢性低氧组急性低氧刺激前后血流动力学指标变化，并行相关分析。结果慢性低氧组PAP明显高于空白对照组（P〈0．05），Psa略有升高，BAF明显降低，推算出肺循环阻力（pulmonary vascular resistance，PVR）和总外周循环阻力（total peripheral resistance，TPR）明显高于空白对照组（P〈0．05）。给予（17％O2）低氧刺激后，空白对照组除了Psa和BAF略有降低外其他指标没有显著性差异；慢性低氧组PAP、PVR升高，Psa、TPR降低。结论慢性低氧可使大鼠肺循环阻力增加，同时肺循环对低氧刺激的敏感性也随之降低。

英文摘要：

Objective To explore the influence of chronic hypoxia on hemodynamics of hypoxia acclimation rats.Methods 20 SD rats were randomly divided into the control group（n= 10）and chronic hypoxic group（n= 10）. The control croup was feeding at 2260 m above sea level, and the chronic hypoxia group was feeding at low pressure oxygen cabin（ simulation for 5000m above sea level）, both groups lasted for 30 days.The hemodynamic indexes, such as the central venous pressure （ CVP）, systematic arterial pressure （ Psa）, pulmonary artery pressure （ PAP ）, blood flow to the aorta（BAF） and left atrial pressure （Pla）were detected after thoracotomy, and then taken the hy- poxic ventilating（ 17% ）for 5 min.The hemodynamic changes were observed before and after acute hypoxia stimula- tion both in the control group and chronic hypoxia group.Results The PAP in chronic hypoxia group was higher than that of the control group（ P〈0.05 ）.The Psa increased slightly and the BAF decreased significantly in chronic hypoxia group.The pulmonary vascular resistance （PVR）and total peripheral resistance （TPR）in chronic hypoxia group were significantly higher than that of in the control group （P〈0.05）.After hypoxic ventilation（ 17% 02 ） cators in control group had not been changed except for Psa and BAF decreased slightly. Moreover, the increased and Psa, TPR decreased significantly in chronic hypoxia group. Conclusion The PVR will chronic hypoxic rats and the sensitivity of acute hypoxia on pulmonary circulation will also be lowed