Hass M A, Massaro D
Oak Asthma Research and Treatment Facility, University of Miami School of Medicine, FL 33136.
Biochem Pharmacol. 1987 Nov 15;36(22):3841-6. doi: 10.1016/0006-2952(87)90447-3.
Adult rats exposed to hyperoxia are protected from lung injury by treatment with bacterial endotoxin. Experiments were undertaken to determine whether endotoxin treatment produces a mitogenic effect on the lung. Endotoxin treatment caused a significant (P less than .05) loss of body weight (8%) in rats exposed to either air or greater than 95% O2 for 24 hr. Therefore, experiments were also undertaken in which both saline- and endotoxin-treated rats were starved for the duration of the experiments to make equal any nutritional imbalance. The rate of DNA synthesis in lung slices from fed rats treated with endotoxin did not differ from that of saline-treated controls. In contrast, lung DNA synthesis in starved rats treated with endotoxin increased 50%. The effect of endotoxin treatment was similar in rats breathing air or greater than 95% O2, and lung protein synthesis generally paralleled lung DNA synthesis. These results indicate that endotoxin does exert a mitogenic effect on the lung and this effect can be masked by the nutritional imbalance resulting from endotoxin administration.
成年大鼠暴露于高氧环境时，用细菌内毒素治疗可保护其免受肺损伤。进行了实验以确定内毒素治疗是否对肺产生促有丝分裂作用。内毒素治疗导致暴露于空气或95%以上氧气环境24小时的大鼠体重显著减轻（P小于0.05）（8%）。因此，还进行了实验，在实验过程中对用盐水和内毒素治疗的大鼠均进行饥饿处理，以平衡任何营养失衡。用内毒素治疗的喂食大鼠肺切片中的DNA合成速率与用盐水治疗的对照组无差异。相反，用内毒素治疗的饥饿大鼠的肺DNA合成增加了50%。内毒素治疗对呼吸空气或95%以上氧气的大鼠的作用相似，肺蛋白合成通常与肺DNA合成平行。这些结果表明，内毒素确实对肺有促有丝分裂作用，并且这种作用可被内毒素给药导致的营养失衡所掩盖。
