Brozmanová M, Hanácek J, Tatár M, Strapková A, Szépe P
Department of Pathophysiology, Jessenius Faculty of Medicine, Comenius University, Martin, Slovak Republic.
Physiol Res. 2002;51(5):529-36.
Toxic influence of high oxygen concentration on pulmonary function and structures has been known for many years. However, the influence of high oxygen concentration breathing on defensive respiratory reflexes is still not clear. In our previous experiments, we found an inhibitory effect of 100 % oxygen breathing on cough reflex intensity in healthy guinea pigs. The present study was designed to detect the effects of hyperoxia on cough reflex in guinea pigs with allergic airway inflammation. In the first phase of our experiment, the animals were sensitized with ovalbumin. Thirty-two sensitized animals were used in two separate experiments according to oxygen concentration breathing: 100 % or 50 % oxygen for 60 h continuously. In each experiment, one group of animals was exposed to hyperoxia, another to ambient air. The cough reflex was induced both by aerosol of citric acid before sensitization, then in sensitized animals at 24 h and 60 h of exposition to oxygen/air in awake animals, and by mechanical stimulation of airway mucosa in anesthetized animals just after the end of the experiment. In contrast to 50 % oxygen, 100 % oxygen breathing leads to significant decrease in chemically induced cough in guinea pigs with allergic inflammation. No significant changes were present in cough induced by mechanical stimulation of airways.
高氧浓度对肺功能和结构的毒性影响已为人所知多年。然而，高氧浓度呼吸对防御性呼吸反射的影响仍不明确。在我们之前的实验中，我们发现100%氧气呼吸对健康豚鼠的咳嗽反射强度有抑制作用。本研究旨在检测高氧对过敏性气道炎症豚鼠咳嗽反射的影响。在实验的第一阶段，用卵清蛋白使动物致敏。根据呼吸的氧气浓度，将32只致敏动物用于两个独立的实验：持续60小时吸入100%或50%的氧气。在每个实验中，一组动物暴露于高氧环境，另一组暴露于环境空气中。在致敏前用柠檬酸气雾剂诱发咳嗽反射，然后在致敏动物清醒状态下暴露于氧气/空气24小时和60小时时诱发咳嗽反射，并在实验结束后立即对麻醉动物的气道黏膜进行机械刺激来诱发咳嗽反射。与50%氧气相比，100%氧气呼吸导致过敏性炎症豚鼠化学诱导咳嗽显著减少。气道机械刺激诱发的咳嗽没有显著变化。
