模拟失重条件下高浓度氧对大鼠肺脏的影响

本实验目的是观察模拟失重与高浓度氧暴露１２－３６ｈ对大鼠肺脏的影响。研究两者的复合效应。实验共用Ｗｉｓｔａｒ大鼠６０只，分为５个组。尾悬吊作为模拟失重的动物模型。

Effects of Simulated Weightlessness and High Concentration Oxygen on Lungs in Rats

Experiments were conducted on 60 Wistar rats devided into 5 groups: control, high concentration oxygen exposure for 12 h, and for 36 h; tail - suspension plus high oxygen exposure for 12 h, and for 36 h. After high oxygen exposure for 12 h, inflammatory cell infiltrations of lung tissue was seen under microscopy. After exposure for 36 h, endothelial endoplasmic reticulum of the cells were swollen and decreased in density; density of mitochondria increased and its structure could not be seen clearly. Suspension combined with hight oxygen induced more severe edema in the lung than that induced by simple high oxygen exposure. There were different degrees of edema in the epithelium, en-dothelium and basement membrane. Wet - to - dry weight ratio of lung tissue increased , but inflammatory reaction was milder than that in simple high oxygen exposure. Activity of angiotensin converting enzyme (ACE) tended to increase after exposure to the combined factors for 36 h . All of these changes indicated that the combined effect of these two factors aggravated the lung damage, so the toxic dose and safety exposure time of oxygen on the ground should be revised for weightlessness condition before using in spaceflight.