Northway W H, Rezeau L, Petriceks R, Bensch K G
Pediatrics. 1976 Jan;57(1):41-6.
Continuous exposure to 100% oxygen at atmospheric pressure for two weeks causes significant alterations in the growth of the lung and the body of newborn mice. These changes can be divided into three phases. The initial phase, which lasts 96 hours, is characterized by inhibition of lung DNA synthesis, diminished total lung DNA, and a decrease in the ratio of lung DNA to body weight. The intermediate phase from 96 to 144 hours is characterized by a sharp increase in mortality, a plateau in body weight, and a minimal lung DNA/body weight ratio. During this period, however, surviving animals show a reversal of the inhibition of DNA synthesis and thus an increase in total lung DNA. The third phase, occurring after 144 hours, is characterized by a continued increase in DNA synthesis and total lung DNA, a gain in body weight, a return of the lung DNA/body weight ratio to control levels, and a sharp decline in mortality. The survival rate of 54% in newborn mice over two weeks contrasts with the near total mortality reported for adult experimental animals similarly exposed. The reversal of the inhibition of lung DNA synthesis in surviving mice suggests either that some newborn animals are inherently resistant to pulmonary oxygen toxicity or that they develop, during a critical exposure period, an adaptive process necessary for their survival.
在常压下持续两周暴露于100%氧气会导致新生小鼠的肺和身体生长出现显著变化。这些变化可分为三个阶段。初始阶段持续96小时，其特征是肺DNA合成受到抑制、肺总DNA减少以及肺DNA与体重之比降低。96至144小时的中间阶段，其特征是死亡率急剧上升、体重稳定以及肺DNA/体重比降至最低。然而，在此期间，存活的动物显示出DNA合成抑制的逆转，从而肺总DNA增加。第三阶段发生在144小时之后，其特征是DNA合成和肺总DNA持续增加、体重增加、肺DNA/体重比恢复到对照水平以及死亡率急剧下降。新生小鼠两周内54%的存活率与同样暴露的成年实验动物几乎全部死亡的报道形成对比。存活小鼠中肺DNA合成抑制的逆转表明，要么一些新生动物天生对肺氧毒性有抵抗力，要么它们在关键暴露期发展出了生存所需的适应性过程。
