Article
Version 1
Preserved in Portico This version is not peer-reviewed
Exhaled Nitric Oxide and Pulmonary Oxygen Toxicity Susceptibility
Version 1
: Received: 23 June 2023 / Approved: 23 June 2023 / Online: 23 June 2023 (13:05:19 CEST)
A peer-reviewed article of this Preprint also exists.
Fothergill, D.M.; Gertner, J.W. Exhaled Nitric Oxide and Pulmonary Oxygen Toxicity Susceptibility. Metabolites 2023, 13, 930. Fothergill, D.M.; Gertner, J.W. Exhaled Nitric Oxide and Pulmonary Oxygen Toxicity Susceptibility. Metabolites 2023, 13, 930.
Abstract
Individual susceptibility to pulmonary oxygen toxicity (PO2tox) is highly variable and currently lacks a reliable biomarker for predicting pulmonary hyperoxic stress. As nitric oxide (NO) is involved in many respiratory system processes and functions, we aimed to determine if expired nitric oxide (FENO) levels can provide an indication of PO2tox susceptibility in humans. Eight U.S. Navy trained divers volunteered as subjects. The hyperoxic exposures consisted of six- and eight-hour hyperbaric chamber dives conducted on consecutive days in which subjects breathed 100% oxygen at 202.65 kPa. Subjects’ individual variability in pulmonary function and FENO was measured twice daily over five days and compared with their post-dive values to assess susceptibility to PO2tox. Only subjects who showed no decrements in pulmonary function following the six-hour exposure conducted the eight-hour dive. FENO decreased by 55% immediately following the six-hour oxygen exposure (n=8, p<0.0001) and by 63% following the eight-hour exposure (n=4, p<0.0001). Four subjects showed significant decreases in pulmonary function immediately following the six-hour exposure. These subjects had the lowest baseline FENO and the lowest post-dive FENO and had clinical symptoms of PO2tox. Individuals with low FENO were the first to develop PO2tox symptoms and deficits in pulmonary function from the hyperoxic exposures. These data suggest that endogenous levels of NO in the lung may protect against the development of PO2tox.
Keywords
hyperoxia; pulmonary function; expired nitric oxide; spirometry; oxygen toxicity; diving; hyperbaric
Subject
Medicine and Pharmacology, Pulmonary and Respiratory Medicine
Copyright: This is an open access article distributed under the Creative Commons Attribution License which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited.
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