摘要
目的观察急性低压缺氧后内皮素前体原（ｐｐＥＴ）和内皮素－１（ＥＴ－１）的变化规律，探讨ＥＴ－１升高的机理。方法将实验大鼠分成三组，观察急性中度低压缺氧３０ｍｉｎ时及６ｈ后ｐｐＥＴ和ＥＴ－１的含量变化，分析其相关性。结果①急性中度低压缺氧３０ｍｉｎ后ｐｐＥＴ和ＥＴ－１均明显升高（Ｐ＜０．０５或０．０１），脱离缺氧后６ｈ，ｐｐＥＴ和ＥＴ－１有轻度下降，但仍未恢复到对照组水平（Ｐ＜０．０５）。②缺氧前对照组ｐｐＥＴ与ＥＴ－１呈明显正相关（ｒ＝０．９３，Ｐ＜０．００１），缺氧３０ｍｉｎ后，ＥＴ－１和ｐｐＥＴ虽明显升高，但二者仍呈明显正相关（ｒ＝０．９０，Ｐ＜０．００１），脱离缺氧后６ｈ，二者有轻度下降，但二者亦呈明显正相关（ｒ＝０．８０，Ｐ＜０．０１）。结论急性低压缺氧可启动ＥＴ基因系统，ＥＴ－１的升高是ｐｐＥＴ合成和释放增加的结果。急性中度低压缺氧对ＥＴ基因启动的时间较长，至少可维持６ｈ以上。
Objective This study was designed to determine the effect of acute hypobaric hypoxia exposures on plasma preproendothelin(ppET) and endothelin (ET 1) levels and to explore the machanism of increase of plasma ET in rats after acute exposures to hypoxia. Methods Thirty Wistar rats served as subjects. They were randomly divided into 3 groups(10 each): control group, experimental group 1 and experimental group 2. The rats of experimental group 1 and 2 underwent acute hypobaric hypoxia (5000 m) for 30 min, and blood samples were collected immediately after hypoxic exposure for group 1, and 6 h after that for group 2. The blood samples of control group was collected after staying in hypobaric chamber for 30 min without ascending. The contents of plasma ppET and ET 1 were measured by radioimmunoassay. Results The results showed that ① both ppET and ET 1 contents increased significantly immediately after 30 min acute hypobaric hypoxia ( P <0.05 or 0.01). Six h later, they showed tendency of lowering, but still significantly higher than initial value. ② the initial contents of ppET and ET 1 showed obviously positive corelation ( r=0.93, P <0.001). Immediately after hypoxia for 30 min, both ppET and ET 1 contents increased significantly, but they still showed obviously positive corelation ( r=0.90, P <0.001). 6 h after hypoxia for 30 min, ppET and ET 1 of contents showed obviously positive corelation too ( r=0.80, P < 0.01). Conclusions The results suggest that the acute hypobaric hypoxia may initiate the gene system of ET 1. The increase of ET 1 is due to the enhancement of synthsis and secretion of ppET. The effect of acute hypobaric hypoxia on preproendothelium can last more than 6 h.
关键词
缺氧
内皮素
大鼠
Acute hypobaric hypoxia Preproendothelin Endothelin Gene expression
