Research on the effect of hyperbaric oxyen combined with glutamine on traumatic brain injury in rats

Objective To investigate the effect of hyperbaric oxygen (HBO) combined with glutamine (GLN) on the prognosis of traumatic brain injury (TBI) in rats.Methods Seven days before the establishment of TBI model,60 SD rats were anesthetized with 1％ pentobarbital sodium (30-50 mg/kg)to establish the intestinal nutritional support model.Six days after gastrotomy,Feeney method was employed to establish the rat model of traumatic brain injury.Then,the animals were randomly divided into 4 groups:the traumatic brain injury group (the TBI group),the TBI + HBO group,the TBI + GLN (glutamine) group,and the TBI + HBO + GLN group,each consisting of 15 animals.The animals in the TBI group and the TBI + HBO group received routine intestinal nutritional support,3 hours after sustaining TBI,and the animals in the TBI + GLN group and the TBI + HBO + GLN group received fortified intestinal nutritional support (containing 2 g of GLN in 100 g feed).The animals in the TBI + HBO group and the TBI + HBO + GLN group were just given one session of HBO therapy,3 hours after TBI,at a pressure of 0.15 MPa(1.5 ATA).Then,at d 1,d 3 and d 7 after TBI,neuronal apoptosis rate of penumbra area was evaluated with in situ end labeling (TUNEL),and Enzyme Linked Immunosorbent Assay was applied to evaluate rat-PA concentrations.The nerve function of the animals was detected by using Balance beam assay and changes in their body mass were monitored with the weighing method.Results One day and 3 days after TBI,neuronal apoptosis rate of penumbra area for the animals of the TBI + HBO group decreased.One day,3 days and 7 days after TBI,neuronal apoptosis rate of penumbra area for the animals of the TBI + HBO + GLN group also decreased.Statistical significance could be noted,when it was compared with the TBI group (P ＜ 0.05 or P ＜ 0.01).Neuronal apoptosis rate of penumbra area for the animals of the TBI + GLN group also decreased,but without statistical significance.For the animals of the TBI + GLN group and the TBI + HBO + GLN,the serum concentration of rat-PA increased 7 days after TBI (P ＜ 0.05),however,statistical significance was seen,when it was compared with the TBI group at the same time points (P ＜ 0.05 or P ＜ 0.01).Nerve function improved significantly.Statistical significance could be seen in the scores of balance beam assay for the animals of the TBI + HBO group 7 days after TBI and the animals of the TBI + HBO + GLN group 3 and 7 days after TBI,when it was compared with the TBI group at the same time points (P ＜ 0.05 or P ＜ 0.01).No statistical significance was noted in the differences of body mass index (BMI).Neuronal apoptosis rate in the animals of the TBI + HBO + GLN group decreased,while serum concentration of rat-PA increased,with the neural function recovered most prominently.Conclusions HBO combined with glutamine in the treatment of TBI could effectively decrease neuronal apoptosis rate,increase serum concentration of rat-PA and improve neural function of the experimental animals,thus improving prognosis. Key words: Hyperbaric oxygen; Glutamine; Traumatic brain injury