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Effect of High Levels of Oxygen and Smoking on the Lungs in Human Volunteers

Effect of Hypoxia and Smoking on Oxidation of Proteins and Nucleic Acids in Human Volunteers

Status
Completed
Phases
Unknown
Study type
Observational
Source
ClinicalTrials.gov
Registry ID
NCT00001464
Enrollment
77
Registered
1999-11-04
Start date
1995-08-22
Completion date
2007-07-10
Last updated
2021-08-27

For informational purposes only — not medical advice. Sourced from public registries and may not reflect the latest updates. Terms

Conditions

Healthy Volunteers

Keywords

Oxygen, Bronchoalveolar Lavage, DNA Repair, Carbonyl Groups, Serum, Human Volunteers

Brief summary

Patients with lung disease experiencing difficulty breathing can be treated with oxygen therapy. This involves the delivery of extra oxygen by a face-mask or through small tubes placed in the nose called nasal prongs. This extra oxygen can have concentrations as high as 100% pure oxygen. The concentration of oxygen in normal air is only 21%. The high concentration of oxygen can help to provide enough oxygen for all of the organs in the body. Unfortunately, breathing 100% oxygen for long periods of time can cause changes in the lungs, which are potentially harmful. Researchers believe that by lowering the concentration of oxygen therapy to 40% patients can receive it for longer periods of time without the risk of side effects. This study is designed to evaluate the effects of oxygen therapy at 100% and 40% for 12 18 hours on the lungs of normal volunteers. Results of this study will help to determine if levels of oxygen therapy currently accepted as being safe may actually be damaging to the lungs.

Detailed description

Stress such as high oxygen or inflammation can result in damage to proteins by processes such as oxidation or alternative regulation of signaling pathways by post-translational modification of proteins (e.g., phosphorylation). Delivery of oxygen in high concentrations to the lungs can result in damage, which is mediated in large part by reactive oxygen species. Inflammation can result in activation of intracellular signaling pathways. This study will evaluate modification of proteins and nucleic acids in bronchoalveolar lavage fluid, bronchial epithelial cells, and peripheral blood of individuals exposed to oxygen or who are smokers. In doing so, it will determine the effects of hyperoxia or inflammation on the lung.

Interventions

None listed

Sponsors

National Heart, Lung, and Blood Institute (NHLBI)
Lead SponsorNIH

Study design

Observational model
CASE_ONLY
Time perspective
PROSPECTIVE

Eligibility

Sex/Gender
ALL
Age
18 Years to 65 Years
Healthy volunteers
Yes

Inclusion criteria

* INCLUSION CRITERIA: History - good overall health without history of recent (within 3 months) acute disease; Physical examination within normal limits; Laboratory evaluation; including complete blood count (CBC), serum electrolyte determinations, clotting times, chest x-ray, pulmonary function testing, and an electrocardiogram (EKG) - within normal limits; Non-smokers defined as having never smoked or not smoked in the past 2 years; Smokers defined as moderate (1 pack per day for 3+ years) or heavy (1-2 packs for 10+ years); Subjects must be willing to make the time commitment necessary for the study.

Exclusion criteria

Any study subject who does not fulfill the criteria for eligibility. Individuals with a history of allergy or adverse reactions to atropine or any local anesthetic; Individuals testing positive for the human immunodeficiency virus or hepatitis virus; Individuals on chronic medications or currently receiving medications; Pregnant or lactating individuals, since the effects of hyperoxia on the fetus are unclear.

Design outcomes

Primary

MeasureTime frameDescription
To determine whether hyperoxia of relatively limited duration (up to l8 hrs) is associated with oxidation of proteins and nucleic acids in lung cells.1 weekTo determine whether hyperoxia of relatively limited duration (up to l8 hrs) is associated with oxidation of proteins and nucleic acids in lung cells.

Countries

United States

Outcome results

None listed

Source: ClinicalTrials.gov · Data processed: Feb 4, 2026