Observation of lung injury and repair during growth and development in rats

1. 研究了产前 1 天至产后 42 天大鼠暴露在高氧环境下的肺部 DNA 含量和 DNA 聚合酶及其 α 和 β 形式的活性变化。结论是：(1) 肺部细胞增殖在出生后的前两周最为活跃，这得到了 DNA 聚合酶 α 活性和 DNA 含量增加的支持，(2) DNA 修复能力、DNA 聚合酶 β 活性在整个产前和产后期间保持恒定。2。研究了重复注射博莱霉素后小鼠肺部 DNA 合成和细胞成分的变化。 (1)重复注射BLM导致肺细胞DNA损伤； (2) DNA 修复功能随之增强，这一点得到了 DNA 聚合酶-β 活性增强的发现的支持； (3) 这些进一步导致细胞增殖，这得到了 DNA 聚合酶-α 活性和 DNA 含量增加的支持。

1. Changes in the DNA content and the activity of DNA polymerase and its alpha and beta forms were studied on the lungs, which were exposured in hyperoxia, of one day prenatal to 42 day postnatal rats. It is concluded that : (1) cellular proliferation in the lung is most active during the first two weeks after birth as supported by increase in both DNA polymerase alpha activity and DNA content, and (2) the capacity for DNA repair, DNA polymerase beta activity throughout the pre and postnatal period remains constant.2. Changes in the DNA synthesis and cellular constituents of mouse lung following repeated bleomycin injections were studied. (1) repeated injections of BLM cause DNA injury in lung cells ; (2) there is a subsequent increase in the DNA repair function as supported by the finding of an increase in DNA polymerase-beta activity ; and (3) these lead further to cell prolifration as supported by the increase in both DNA polymerase-alpha activity and DNA content.