Abstract:

Objective

To investigate the effect of hypoxic preconditioning (HPC) on the expression of hypoxia-inducible factor-1α, glucose transporter-3 and neuronal survival in cerebral cortex in rats with traumatic brain injury (TBI).

Methods

A total of 120 SD rats were randomly assigned to control group (CON, n=12), traumatic brain injury group (TBI, n=54) and traumatic brain injury after HPC group (HPCT, n=54). The rats of TBI group were established the TBI model by Feeney free falling dart impact method; The rats of HPCT group were treated with HPC (50.47 kPa,3 h/d,3 d)firstly,and then establish the HPCT model by Feeney free falling dart impact method.Detect the expression of HIF-1α、GLUT-3 mRNA and protein around the contusion focus on 1h, 4h, 8h,12h, 1d, 3d, 7d, 14d post-injury by RT-PCR and Western blotting, analysis the relevance between HIF-1α and GLUT-3, observe the neuronal survival situation of NeuN positive expression rate around the contusion focus by immunohistochemistry in 14 d post-injury. Take single factor analysis of variance among groups, analyzed by multiple comparisons with LSD method,correlation analysis with Pearson correlation analysis method, set P＜0.05 as the statistically significant difference.

Results

TBI group, both HIF-1α and GLUT-3 increased expression significantly on 4h, 8h, 12h, 1d and 3d post-injury(P＜0.05).HPCT group,both HIF-1α and GLUT-3 increased expression on 1h post-injury,the expression of HIF-1α and GLUT-3 on 4h to 7d post-injury and the count of NeuN positive cells 14d post-injury were both significantly higher than TBI group (P＜0.05). Correlation analysis showed that the expression of HIF-1α and GLUT-3 mRNA and protein were positive correlated.

Conclusion

HPC can induce the expression of HIF-1α in the cortical brain tissue, raise the expression of GLUT-3 mRNA and protein,and improve the acute neuronal survival rate post-injury of TBI.

Key words: Brain injuries, Wounds and injuries, Hypoxia-inducible factor Ⅰ, alpha subunit, Glucose transporter type 3