Hydrogen inhalation is neuroprotective and improves functional outcomes in mice after intracerebral hemorrhage
Manaenko A, Lekic T, Ma Q, Ostrowski RP, Zhang JH, Tang J. · Acta Neurochirurgica Supplement. 2011;111:179-183.
Study at a glance
Preclinical
Male CD-1 mice weighing 30-35 g after collagenase injection into the right basal ganglia.
Inhalation of 2.0% H₂ for one or two hours in the acute study; the one-hour exposure was used for the delayed study. · H₂ concentration was 2.0%. Total gas flow, carrier O₂ concentration, H₂ mL/min and O₂ mL/min were not reported.
One- or two-hour exposure; brain edema and neurological outcomes at 24 or 72 hours.
At 24 hours, one hour of H₂ reduced edema and improved all three tests. Two hours did not reduce edema and improved only some neurological tests. At 72 hours, one-hour H₂ showed non-significant tendencies rather than confirmed benefit; the authors concluded the acute regimen was insufficient for delayed outcomes.
Small mouse groups, collagenase model, one sham group reused across time points, limited outcome set, unexpected lack of dose-duration relationship and no durable statistically confirmed effect at 72 hours. NIH support was reported; authors declared no conflicts.
What kind of evidence is this?
Preclinical
Controlled acute and delayed mouse intracerebral-hemorrhage experiments
Other neurological conditions
Inhaled H₂
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
Male CD-1 mice weighing 30-35 g after collagenase injection into the right basal ganglia.
30 mice across acute and delayed studies. The 24-hour groups used n=5 each for sham, vehicle, one-hour H₂ and two-hour H₂; delayed groups used n=5 and reused the same sham group.
One- or two-hour exposure; brain edema and neurological outcomes at 24 or 72 hours.
Inhalation of 2.0% H₂ for one or two hours in the acute study; the one-hour exposure was used for the delayed study.
Inhaled 2% H₂ — not Brown's gas. The article does not state the carrier-gas composition.
H₂ concentration was 2.0%. Total gas flow, carrier O₂ concentration, H₂ mL/min and O₂ mL/min were not reported.
Not reported — total mixture flow is absent.
Carrier O₂ concentration and flow were not reported and are not inferred.
Sham surgery and intracerebral hemorrhage with room-air vehicle exposure.
Outcomes and reported result
Regional brain water content and modified Garcia, beam-balance and wire-hanging neurological tests.
At 24 hours, one hour of H₂ reduced edema and improved all three tests. Two hours did not reduce edema and improved only some neurological tests. At 72 hours, one-hour H₂ showed non-significant tendencies rather than confirmed benefit; the authors concluded the acute regimen was insufficient for delayed outcomes.
The complete free PMC chapter was checked for total allocation, exposure concentration/durations, missing gas flows, acute positive and delayed null findings, funding and conflict declaration.
A reported association, difference or mechanism is not automatically a clinical benefit.
Limitations and applicability
Small mouse groups, collagenase model, one sham group reused across time points, limited outcome set, unexpected lack of dose-duration relationship and no durable statistically confirmed effect at 72 hours. NIH support was reported; authors declared no conflicts.
Experimental intracerebral hemorrhage in male mice; it does not establish acute stroke treatment in humans.
No single-study GRADE certainty rating is assigned. Read how records and evidence assessments are prepared.
Sources and record status
PMID: 21725752 · DOI: 10.1007/978-3-7091-0693-8_30
Free full chapter in PubMed Central.
Complete PMC chapter and PubMed metadata; full-text extraction checked 9 August 2026.
10 August 2026
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