水素ガス吸入がアレルギー性結膜炎モデルマウスに与える影響
Using an ovalbumin-sensitized mouse model of allergic conjunctivitis, this study examined whether inhaled hydrogen gas could modify allergic ocular responses. Mice received intraperitoneal ovalbumin sensitization followed by daily ocular instillation of the antigen. After antigen challenge, animals in the hydrogen group were exposed to hydrogen gas. Two primary outcomes were assessed: eye-scratching frequency as a surrogate for ocular pruritus, and eosinophil counts in tear fluid. Hydrogen gas exposure significantly reduced antigen-induced scratching behavior and attenuated the rise in tear eosinophil numbers. The authors propose that reactive oxygen species play a central role in both pruritic signaling and eosinophil recruitment, and that hydrogen gas scavenges these species to suppress allergic conjunctival inflammation.
Hydrogen gas is proposed to scavenge reactive oxygen species, thereby suppressing pruritic signaling pathways and reducing eosinophil migration into conjunctival tissue.
For inhalation applications of molecular hydrogen, the lower flammability limit (LFL) deserves careful handling. The classical 4% figure applies to closed-system mixtures; the practical inhalation-environment threshold is 10%. Even pure-hydrogen output (the UFL 75% paradox) passes through the flammable range at the air–gas boundary. High-concentration (66% / 100%) inhalers are documented in the Japanese Consumer Affairs Agency accident-information database and are not recommended.
See also:
https://h2-papers.org/en/papers/42101321