The effects of inhaling hydrogen gas on macrophage polarization, fibrosis and lung function in mice with bleomycin-induced lung injury
Aokage T et al. · BMC Pulm Med. 2021;21:339.
Study at a glance
Preclinical
Mice with intratracheal bleomycin-induced lung injury
3.2% H₂ in air for 6 hours every day beginning on the day of bleomycin administration · 3.2% H₂ in air.
6 hours/day for 7 or 21 days
The article reports higher static compliance, lower elastance and less fibrosis-related and inflammatory change after 21 days of H₂ exposure.
Preclinical bleomycin model, prolonged daily chamber exposure, multiple time points and outcome-specific sample sizes.
What kind of evidence is this?
Preclinical
Controlled mouse bleomycin-lung-injury experiment with 7- and 21-day comparisons
Respiratory health
Other forms
Information not yet classified
Some editorial classification fields are still pending. The source-reported outcomes and result are shown below; Hydrogenology does not infer a positive or negative signal from prose automatically.
Methods
Mice with intratracheal bleomycin-induced lung injury
The article used multiple outcome-specific cohorts; complete total allocation is in a supplementary table and remains to be consolidated
6 hours/day for 7 or 21 days
3.2% H₂ in air for 6 hours every day beginning on the day of bleomycin administration
H₂ diluted in air — not Brown’s gas.
3.2% H₂ in air.
Bleomycin-injured mice exposed to air and corresponding non-injured controls
Outcomes and reported result
Respiratory physiology, CT and histology, fibrosis, cytokines and macrophage phenotypes
The article reports higher static compliance, lower elastance and less fibrosis-related and inflammatory change after 21 days of H₂ exposure.
Concentration, duration, principal physiological and tissue results, funding and conflicts checked in the open-access full text; total sample allocation awaits supplementary-table consolidation.
A reported association, difference or mechanism is not automatically a clinical benefit.
Limitations and applicability
Preclinical bleomycin model, prolonged daily chamber exposure, multiple time points and outcome-specific sample sizes.
Bleomycin-induced inflammatory and fibrotic lung injury in mice, not human pulmonary fibrosis.
No single-study GRADE certainty rating is assigned. Read how records and evidence assessments are prepared.
Sources and record status
PMID: 34719405 · DOI: 10.1186/s12890-021-01712-2
Open-access full text is available through PMC and the publisher.
Open-access PMC/publisher full text and PubMed record; no retraction or expression of concern was shown in the checked records on 7 August 2026.
10 August 2026
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