Protective effects of hydrogen on fetal brain injury during maternal hypoxia

Abstract

This study aimed to investigate the effects of hydrogen on fetal brain injury during maternal hypoxia. Pregnant rats (n = 12, at gestational day 17) were randomly assigned into three groups; air, hypoxia, and hypoxia plus hydrogen groups were put into a chamber and flushed with room air (21% O 2 and 79% N2), hypoxia (8% O2 and 92% N 2), and hypoxia with hydrogen mixture (2% H2, 8% O 2 and 90% N2), respectively, for 4 consecutive hours. After birth, body and brain weights, body-righting reflex, and negative geotropism of neonates were measured, and then pups were killed at days 1 and 7. Oligodendrocytes were studied at post-natal day 1 by immunohistochemistry. We found significant decreases in body weight in the hypoxia group (P < 0.05 vs. room air group), but not in the hypoxia plus hydrogen group (P > 0.05 vs. room air group). Even though brain weight was not different among groups, the brain weight to body weight ratio in the room air group was significantly (P < 0.05) lower than that in the hypoxia alone or hypoxia plus hydrogen groups. Body-righting reflex at day 1 and negative geotropism at days 3-4 showed deficiency in hypoxia animals when compared with the room air group (P < 0.05). Hydrogen treatment improved the body-righting reflex and negative geotropism (P < 0.05 vs. room air group). The above-mentioned functional changes caused by hypoxia were not associated with morphology and cell death of oligodendrocytes. Therefore, the maternal hypoxia-induced body weight loss, and functional abnormalities and hydrogen treatment during hypoxia offered a protective effect and improved functions in neonates. © 2011 Springer-Verlag/Wien.