模拟失重对肺动脉反应性的影响

Effects of simulated weightlessness on reactivity of pulmonary artery

摘要: 目的: 研究模拟失重对肺动脉反应性的影响,探讨立位耐力降低的发生机制。方法: 采用尾悬吊模拟失重大鼠模型模拟微重力效应,制备离体肺动脉环测定其对几种血管活性物质的反应性变化。结果: 与对照组相比,尾悬吊14 d大鼠肺动脉对KC l(68 mmol/L)和苯肾上腺素(10^-9～10^-5mmol/L)的收缩反应性明显下降,对乙酰胆碱(10^-9～10^-5mmol/L)的舒张反应性明显增强。结论: 模拟失重14 d后肺动脉收缩反应下降,舒张反应增强;肺动脉收缩反应的下降可能促进了立位耐力降低的发生。

Abstract: Objective: To study the effects of simulated weightlessness on reactivity of pulmonary artery.Methods: Rat tail-suspension was used to simulate effects of microgravity.The changes in responses of pulmonary artery to several vasoactive agents were determined by using in vitro vessel rings perfusion technique.Results: Compared with the control group,the contractile responses of pulmonary artery to potassium chloride（KCl,68M）and phenylephrine(PE,10^-9～10^-5M)were markedly diminished after 14day tail-suspension,while the vasoactive responses to acetylcholine(Ach,10^-9～10^-5M)were markedly enhanced.Conclusion: The contractile responsiveness is attenuated and the dilatory responsiveness is enhanced in the pulmonary arteries of rats after simulated weightlessness;impaired contractile responsiveness may contribute to orthostatic intolerance.