尾部悬吊大鼠肺动脉和胸主动脉血管反应性及一氧化氮合酶抑制剂的影响  

Reactivity of Pulmonary Arteries and Thoracic Aortae in rats under Tail-suspension and the Effects of NOS Inhibitor.

作　　者：汪德生[1] 袁敏[1] 李志利[1] 袁明[1] 刘朝霞[1] 曹毅[1] 仝飞舟[1] 

机构地区：[1]航天医学工程研究所,北京100094

出　　处：《航天医学与医学工程》2005年第1期6-11,共6页Space Medicine & Medical Engineering

基　　金：中国人民解放军总装备部重点技术课题(01101307)

摘　　要：目的进一步明确大小循环动脉对模拟微重力(simulatedmicrogravity,SM)适应机理,阐明SM后立位耐力降低机理,为SM后立位耐力降低寻找新的对抗措施。方法-30°尾部悬吊(TS)大鼠模拟微重力的生理效应。尾部悬吊7d(TS7d)和14d(TS14d)后的肺动脉(PA)和胸主动脉(TA)环对68 mmol/LKCl、累加浓度的苯肾上腺素(PE)和乙酰胆碱(ACh)的反应性作了观察。加入10-5mol/LNOS抑制剂N-硝基 L 精氨酸甲酯(N nitro L argininemethylester,L NAME)孵育20min后重复检测对PE的收缩反应和ACh的舒张反应。结果TS7d、TS14d大鼠PA和TA对KCl及PE的收缩反应非常显著降低;TS7d大鼠PA和TA对ACh的舒张反应显著或非常显著增强,TS14d大鼠PA无变化,TS14dTA仅有增强趋势。加入10-5mol/LL NAME后TS7d、TS14d大鼠PA对PE的收缩反应3组无差异,TS7d、TS14d大鼠TA对PE的收缩反应仍有降低;TS7dPA对ACh的舒张反应显著或非常显著 降低,其余无变化。结论TS大鼠PA和TA收缩反应的降低可能归因于内皮舒张功能的增强。10-5mol/LL NAME可逆转TS后大鼠PA和部分逆转TA的收缩反应降低的实事表明其对内皮细胞的舒张功能有抑制作用,可用于抑制立位耐力降低。Objective To further disclose mechanisms in adaptation of pulmonary and systemic arteries to simulated microgravity (SM), so as to elucidate the mechanisms accounting for orthostatic intolerance after SM, and to explore a new kind of countermeasure for orthostatic intolerance. Method -30° tail suspended (TS)rats were used as the model to simulate the physiological effects of microgravity. Vasoreactivity changes of rings sectioned from pulmonary artery (PA) and thoracic aorta (TA) to 68 mmol/L KCl, plus phenylephrine (PE) and acetylcholine (ACh) were observed after 7 d and 14 d tail-suspension. After preconditioning with 10 -5 mol/L N-nitro-L-arginine methylester ( L-NAME) for 20 min, vasoreactivity changes of PA and TA to PE and ACh were respectively repeated. Result The contractile responsiveness of PA and TA to KCl and PE decreased significantly or very significantly after TS7d and TS14d. The dilatory reactivity of PA and TA to ACh after TS7d had a significant or very significant increase, but reactivity of PA showed no change and TA showed only a tendency to increase after TS14d. After preconditioning with 10 -5 mol/L L-NAME, responsiveness of PA to PE after TS7d and TS14d had no difference among the three groups, but responsiveness of TA to PE after TS7d and TS14d had a significant decrease. The dilatory reactivity of PA after TS7d decreased significantly or very significantly, and the remains showed no significant change. Conclusion The decrease of contractile responsiveness of PA and TA might be due to the increased dilatory function of the endothelial cells. The fact that 10 -5 mol/L L-NAME reversed the decrease of contractile responsiveness of PA and partly of TA after tail suspension implicates that there might be an inhibitory action on the dilatory function of the endothelial cells. The NOS inhibitors may be helpful in preventing orthostatic intolerance.

关 键 词：失重模拟 尾吊 动脉 血管反应性 立位耐力 对抗措施 

分 类 号：R852.22[医药卫生—航空、航天与航海医学]