[The dynamically changes of COX-2 and the gene expression of COX-2 mRNA after traumatic brain injury in rats]

To illuminate the pathology of traumatic brain injury(TBI) and to better understand the relationship between the expression of COX-2 and the time course of TBI.

Immunocytochemical staining, double-labeled with the anti-COX-2 antibody and either the neuron-specific antibody NeuN or the astroglial-specific marker GFAP, in situ hybridization and computer image analysis were used.

Results from immunohistochemistry indicated time-dependent staining changes of neuronal plasma. The immunostained cells were faint at control cortex, mostly were neurons. The immunostained cells appeared to be darkly stained 30 min after TBI for extended periods of time and reached the maximum at 2 d after injury, reached another peak (P < 0.05) at 4 d post-injury. The darker cells persisted in a high level, significant differences (P < 0.05) even presented between control and 15 d post-injury. The COX-2 mRNA expression was faint at control cortex. The expressions of COX-2 mRNA appeared to be darkly stained 15 min after TBI for extended periods of time and reached the maximum (P < 0.05) at 1 d post-injury, reached another peak (P < 0.05) at 3 d post-injury, and significant differences (P < 0.05) even presented between control and 7 d post-injury, but not 15 d post-injury.

The results of this study indicated that the expression of COX-2 mRNA and protein had a possible relationship with the extended periods of time after TBI. It might have some relationship between the expression of COX-2 and secondary brain injury after TBI.