EN
Encephalopathy caused by birth asphyxia results in significant mortality and long-term morbidity. In our previous studies we proved that HBO reduces brain damage in experimental model of birth asphyxia by almost 60%. The aim of present study was to evaluate the effect of hyperbaric oxygen (HBO) on reactive oxygen species (ROS) production and antioxidative enzymes activities – catalase (CAT) and glutathione peroxidase (Gpx) in 7-day old rat brain after hypoxia-ischemia (H-I). In the experimental model of H-I the left (ipsilateral) common carotid artery ligation is followed by 75 min hypoxia. HBO (2,5 ATA) was applied 1, 3 or 6 h after H-I for 60 min. Treatment was repeated for 3 following days. DCF test showed that H-I causes almost 4-fold increase in ROS production in ipsilateral hemisphere, while HBO reduced it by 40%, 24% and 18%, applied 1, 3 and 6 h after H-I, respectively. H-I resulted in 32% increase in catalase activity, probably as a compensation to high ROS concentration. HBO treatment reduced this increase to 4, 5 and 16%, respectively, which is probably a consequence of reduced oxygen radicals production. Similar pattern was observed in activity of Gpx. Our results suggest that HBO reduce synthesis of ROS (which manifests in decreased DCF fluorescence) and also decrease antioxidative enzymes activity. This may be one of the mechanism of HBO neuroprotective and diminishing brain injury effect.