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.
What kind of evidence is this?
Preclinical
Controlled acute and delayed mouse intracerebral-hemorrhage experiments
Other neurological conditions
Inhaled H₂
Not reported in this record.
Not reported in this record.
Methods at a glance
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. Null findings, outcome type, study design and precision all matter.
Cautions 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.
Not reported in this record.
Not reported in this record.
Not reported in this record.
No single-study GRADE certainty rating is assigned. Certainty is assessed by important outcome across a complete eligible evidence set, not by attaching a final grade to one source.
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.
2026-08-10