Combination of hyperbaric oxygen therapy and brain-derived neurotrophic factor in treating hypoxic-ischemic brain injury in neonatal rats

Objective To investigate the protective effects of hyperbaric oxygen (HBO) therapy in combination with intracerebro-ventricular administration of brain-derived neurotrophic factor (BDNF) on hypoxic-ischemic brain injury(HIBI) in neonatal rats.Methods Seven-day-old Sprague-Dawley rats were randomly divided into HIBI+BDNF+HBO group (A),HIBI+BDNF+normoxic hyperbaric nitrogen group (B),mere HIBI group (C),sham-operated group (D) and normal group (E).BDNF was microinjected intracerebro-ventricularly into rat pups(0.5 μg),and followed by HBO therapy (A) or normoxic hyperbaric nitrogen (B) shortly after HIBI was produced by the ligation of left common carotid artery followed by a 2.5 h inhalation of humidified 8% O\-2+92% N\-2 at 37 °C .Changes of brain edema,levels of malondialehyde (MDA) and neuronal apoptosis of the cortex and hippocampus were investigated.Results Brain edema,levels of MDA and neuronal apoptosis were significantly decreased in both group A and group B,compared with group C.More obvious attenuation of brain edema and neuronal apoptosis was seen in group A than in group B.Brain edema in group A was decreased to nearly as low as the level in group D.No significant difference in MDA level existed between group A and group B.Conclusions The combination of HBO therapy and intracerebro-ventricular administration of BDNF exhibits a beneficial effect on the recovery of HIBI,which is better than that of BDNF injection alone.This study indicates a synergistic action of HBO and BDNF in the HIBI experimental therapy.