Development of a novel porcine ischemia/reperfusion model inducing different ischemia times in bilateral kidneys-effects of hydrogen gas inhalation.
左右腎臓に異なる虚血時間を導入した新規ブタ虚血再灌流モデルの開発と水素ガス吸入の効果
Abstract
To investigate renal ischemia-reperfusion injury (IRI), a novel porcine model was developed in which the left and right kidneys were subjected to 120 and 60 minutes of ischemia, respectively, within the same animal. All four animals survived the 3-month observation period without mortality. Separate evaluation of each kidney was achieved through individual renal vein blood sampling and intraoperative biopsy. Degraded DNA released from the kidneys immediately after IRI and subsequent renal fibrosis at 3 months both increased proportionally with ischemia duration. Hydrogen gas inhalation showed a tendency to suppress the release of degraded DNA—an acute IRI marker—although this effect did not reach statistical significance. Histopathological differences between hydrogen-treated and control animals were not clearly evident. This bilateral differential-ischemia model provides two independent data points per animal and enables safe long-term porcine experiments.
Mechanism
Inhaled hydrogen gas showed a trend toward reducing degraded DNA release from kidneys following ischemia-reperfusion, suggesting possible reactive oxygen species scavenging as a mechanism underlying acute renal IRI attenuation.
Bibliographic
- Authors
- Kinoshita Y, Shirakawa K, Sano M, Yokoo T, Kume H, Kobayashi E
- Journal
- Transl Androl Urol
- Year
- 2022
- PMID
- 35558259
- DOI
- 10.21037/tau-21-1164
- PMC
- PMC9085936
Tags
Delivery context
In air, molecular hydrogen is reported to be combustible across approximately **4% (LFL, lower flammability limit) to 75% (UFL, upper flammability limit)**. Among high-concentration hydrogen inhalers, 66% output sits inside this range, and even pure-hydrogen (100%) output forms a 4–75% concentration-gradient layer at the device–air boundary (the UFL 75% paradox). Engineering principle would therefore call for operation below LFL (the classical 4%); that figure, however, was measured under closed, pre-mixed, static conditions. For the open, dynamic inhalation environment, the empirical value reported in the literature is **10%**, which is the figure referenced in practice as the operating ceiling. The 66% / 100% output devices are recorded in the Japanese Consumer Affairs Agency accident-information database, and from these considerations are not recommended.
Safety notes
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