尾部悬吊7d大鼠肺动脉反应性的变化

目的阐明模拟微重力因素对肺循环局部调节功能的影响。方法采用尾部悬吊大鼠模型模拟微重力效应,制备离体动脉环测定肺动脉对几种血管活性物质的反应性变化。结果与对照组相比,尾部悬吊7d内皮完整组大鼠肺动脉对氯化钾（10～70mmol/L）的收缩反应无显著性变化,对苯肾上腺素（10

Changes in Vasoreactivity of Rat Pulmonary Artery after 7 d Tail-suspension

Objective: To clarify the effects of simulated microgravity on the local regulating function of the pulmonary circulation. Method: Rat tail-suspension (TS) was used as the animal model to simulate the effects of microgravity. The changes in responses of pulmonary artery to several vasoactive agents were determined by using in vitro vessel rings perfusion technique. Result: As for the endothelium-intact vessel rings from TS group compared with those from the control (C) group, the contractile responses of pulmonary artery to potassium chloride (KCl, 10 ~ 70 mmol/L) did not change obviously after 7 d tail-suspension, which were markedly diminished as to phenylephrine (PE, 10(-9) ~ 10(-5) mol/L). The vasodilatory responses to acetylcholine (ACh, 10(-9) ~ 10(-5) mol/L) were markedly enhanced, which did not change obviously as to captopril (Cap, 10(-5) ~ 3 x 10(-3) mol/L). The vasoreactivity of endothelium-removed pulmonary artery rings to all vasoactive agents did not change after 7 d tail-suspension as compared with those from control rats. Conclusion: The release of nitric oxide (NO) by rat pulmonary arterial endothelium was enhanced after 7 d tail-suspension. The vasodilatory function of pulmonary artery was enhanced.