Conflicting findings on the effectiveness of hydrogen therapy for ameliorating vascular leakage in a 5-day post hypoxic-ischemic survival piglet model.

Neonatal hypoxic-ischemic encephalopathy (HIE) is a major cause of morbidity and mortality in newborns in both high- and low-income countries. The important determinants of its pathophysiology are neural cells and vascular components. In neonatal HIE, increased vascular permeability due to damage to the blood-brain barrier is associated with seizures and poor outcomes in both translational and clinical studies. In our previous studies, hydrogen gas (H ₂ ) improved the neurological outcome of HIE and ameliorated the cell death. In this study, we used albumin immunohistochemistry to assess if H ₂ inhalation effectively reduced the cerebral vascular leakage. Of 33 piglets subjected to a hypoxic-ischemic insult, 26 piglets were ultimately analyzed. After the insult, the piglets were grouped into normothermia (NT), H ₂ ventilation (H ₂ ), therapeutic hypothermia (TH), and H ₂ combined with TH (H ₂ -TH) groups. The ratio of albumin stained to unstained areas was analyzed and found to be lower in the H ₂ group than in the other groups, although the difference was not statistically significant. In this study, H ₂ therapy did not significantly improve albumin leakage despite the histological images suggesting signs of improvement. Further investigations are warranted to study the efficacy of H ₂ gas for vascular leakage in neonatal HIE.
(© 2023. The Author(s).)