Estimation of the hydrogen concentration in rat tissue using an airtight tube following the administration of hydrogen via various routes
Liu C, Kurokawa R, Fujino M, Hirano S, Sato B, Li XK. · 2014.
What kind of evidence is this?
Preclinical
Controlled rat pharmacokinetic-distribution study
Other molecular hydrogen research
Inhaled H₂
Route- and concentration-dependent distribution signal.
Animal pharmacokinetic and tissue-distribution outcomes.
Methods at a glance
Rats receiving molecular hydrogen by several administration routes.
Route-specific animal and tissue counts were checked; no single consolidated total is reported.
Acute administration with serial tissue measurements.
Hydrogen inhalation and other article-specified routes, with tissue hydrogen measured in airtight sampling tubes.
Inhaled H₂ and H₂ delivered by other tested routes.
The article compared multiple gas concentrations and administration conditions.
Article-specific chamber delivery; no single flow applies to every arm.
Carrier conditions varied by administration arm.
Baseline and route or concentration comparisons.
Outcomes and reported result
Hydrogen concentrations in blood and multiple tissues.
Blood and tissue hydrogen rose after administration, with magnitude and time course differing by route and inhaled concentration.
The full article was checked for methods, intervention details, outcomes, positive and null findings, funding and conflicts. This record does not imply medical efficacy.
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
Pharmacokinetic animal study; tissue concentrations are not evidence of therapeutic benefit.
The reported rat administration and sampling methods only.
SYRCLE animal-study tool — preliminary
Some concerns
Controlled exposure comparisons were used, but allocation, blinding and assay-selection details were incompletely reported.
Sequence generation checked where reported · Allocation concealment generally unclear · Personnel blinding generally unclear · Outcome-assessor blinding generally unclear · No prospectively registered analysis plan identified
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: 24975958 · DOI: 10.1038/srep05485
A free full article is available through PubMed Central.
Official PubMed Central full article and PubMed bibliographic record; source identity, methods, intervention, results, funding and conflicts checked 10 August 2026.
2026-08-10