The reason for the amelioration of N-methyl-N-nitrosourea-induced retinitis pigmentosa in rats by hydrogen-rich saline
Yan WM, Chen T, Wang XC, Qi LS, Zhao GH, Yang GQ, Ma YF, Tao Y, Zhang L, Zhang ZM. · International Journal of Ophthalmology. 2017;10(10):1495-1503.
What kind of evidence is this?
Preclinical
Randomized three-group controlled rat study
Eye health
Other forms
Not reported in this record.
Not reported in this record.
Methods at a glance
Seventy-two rats allocated to normal, MNU retinal-degeneration model, and MNU plus H₂-rich saline groups.
72 rats, n=24 per group. Functional/histological time-point analyses used n=6 per group and molecular assays commonly used n=3 per group.
Daily pretreatment for 14 days plus continued dosing until day-1 or day-3 assessment after MNU.
H₂-rich saline 10 mL/kg intraperitoneally once daily from 14 days before MNU administration until sacrifice one or three days afterward.
H₂ dissolved in saline — H₂ only, not Brown's gas.
Purified hydrogen was dissolved in saline for six hours at 0.4 MPa; solution was stored at 4°C, made weekly and confirmed by gas chromatography to remain above 0.6 mmol/L.
Not applicable — intraperitoneal saline, not gas inhalation.
No O₂ was co-delivered as part of the intervention.
Normal rats and MNU model rats receiving equal-volume normal saline.
Outcomes and reported result
Outer nuclear-layer thickness, electroretinographic b-wave, retinal microglia/Iba1 and Sirt1 mRNA and protein.
H₂-rich saline preserved retinal structure and b-wave amplitude and was associated with higher Sirt1 by day 3. Microglial/Iba1 measures were higher than the untreated model on day 1 but lower by day 3; Sirt1 mRNA was higher at both points but statistically significant at day 3, and Sirt1 protein differed significantly at day 3. The short study did not test inherited retinitis pigmentosa or durable vision.
The complete free PMC article was checked for allocation, H₂ preparation and concentration, dose, prophylactic schedule, structural, functional and molecular results including time-dependent/null findings, funding and conflict declarations.
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
Chemical retinal-injury model, prophylactic H₂ exposure beginning 14 days before injury, short one-to-three-day follow-up, small molecular assay samples and no human participants. Chinese national/provincial grants funded the work; every author declared no conflict of interest.
Acute MNU-induced photoreceptor degeneration in rats; it does not establish treatment for inherited retinitis pigmentosa in people.
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: 29062766 · DOI: 10.18240/ijo.2017.10.03
Free full article in PubMed Central.
Complete PMC article and PubMed metadata; full-text extraction checked 9 August 2026.
2026-08-10