Delayed Neurovascular Dysfunction Is Alleviated by Hydrogen in Asphyxiated Newborn Pigs

Ferenc Domoki, Gabor Remzso, Janos Nemeth, Orsolya Olah, Valeria Toth-Szuki, Viktoria Kovacs, Viktoria Varga

Read more:

DOI: 10.1159/000348445 DOI is the universal ID for this study.

This link will take you to the full study.


Background: The neurovascular unit encompasses the functional interactions of cerebrovascular and brain parenchymal cells necessary for the metabolic homeostasis of neurons. Previous studies indicated marked but only transient (1-4 h) reactive oxygen species-dependent neurovascular dysfunction in newborn pigs after severe hypoxic/ischemic (H/I) stress contributing to the neuronal injury after birth asphyxia. Objectives: Our major purpose was to determine if neurovascular dysfunction would also occur later, at 24 h after a milder H/I stress. We also tested if the putative hydroxyl radical scavenger hydrogen (H2) exerted neurovascular protection.

Methods: Anesthetized, ventilated piglets were assigned to three groups of 9 animals: time control, asphyxia/reventilation with air, and asphyxia/reventilation with air +2.1% H2 for 4 h. Asphyxia was induced by suspending ventilation for 8 min. Cerebrovascular reactivity (CR) of pial arterioles was determined using closed cranial window/intravital microscopy 24 h after asphyxia to the endothelium-dependent cerebrovascular stimulus hypercapnia, the neuronal function-dependent stimulus N-methyl-D-aspartate (NMDA), norepinephrine, and sodium nitroprusside. The brains were subjected to histopathology.

Results: Hemodynamic parameters, blood gases, and core temperature did not differ significantly among the experimental groups. In the early reventilation period, the recovery of electroencephalographic activity was significantly better in H2-treated animals. Asphyxia/reventilation severely attenuated CR to hypercapnia and NMDA; however, reactivity to norepinephrine and sodium nitroprusside were unaltered. H2 fully or partially preserved CR to hypercapnia or NMDA, respectively. Histopathology revealed modest neuroprotection afforded by H2. Conclusions: Severe stimulus-selective delayed neurovascular dysfunction develops and persists even after mild H/I stress. H2 alleviates this delayed neurovascular dysfunction that can contribute to its neuroprotective effect.

Publish Year 2013
Country Hungary
Rank Positive
Journal Neonatology
Primary Topic Brain
Secondary TopicBrain Injury
Model Pig
Tertiary TopicAsphyxial Encephalopathy
Vehicle Gas
pH N/A
Application Inhalation