中文摘要：

目的研究不同时间的间歇性低氧对离体小鼠胸主动脉舒张功能的影响。方法将离体的胸主动脉分为对照组和间歇性低氧组（IH组）,分别放入正常培养箱和IH培养箱内培养。应用血管张力测定技术,观察间歇性低氧6、12、24 h对离体培养的小鼠胸主动脉舒张功能的影响。结果与对照组相比,间歇性低氧6 h的血管内皮舒张功能差异无统计学意义;间歇性低氧12 h和24 h的血管内皮依赖性舒张明显减弱（P〈0.01）,内皮非依赖性舒张低浓度（1~10nmol/L）表现减弱,增大硝普钠浓度,内皮非依赖性舒张差异无统计学意义。结论长时间间歇性低氧培养血管可以使离体血管内皮功能紊乱和血管平滑肌受损。

英文摘要：

Objective To investigate the effect of varying degrees of intermittent hypoxia （IH） on the vasodilation of isolated thoracic aorta in mice. Methods The the thoracic aorta in vitro were divided into control group and in- termittent hypoxia （IH） group, which were cultured in normal incubator and intermittent hypoxia incubator, re- spectively. Then the diastolic effect of the thoracic aorta in IH condition（ 6, 12, 24 h ） in vitro were observed by the vascular tension measurement （myography）. Results Compared with the control groups, the endothelium-de- pendent vasodilation of thoracic aorta that exposed to IH 6 h was not changed while IH 12 h and 24 h were signifi- cantly decreased （ P 〈 0. 01 ） , However the endothelium-dependent vasodilation induced by sodium nitroprusside （SNP） at low concentrations （ 1 - 10 nmol/L） were decreased. With the increasing concentration of SNP, there was no difference in endothelium independent relaxation between the IH groups and control groups. Conclusion The isolated thoracic aorta that exposed to prolonged intermittent hypoxia can cause vascular abnormity due to the dysfunction of endothelium and vascular smooth muscle.