Objective     To investigate the expression alternation of nuclear factor erythroid 2-related factor 2 (Nrf2)

hemeoxygenase-1 (HO-1) and NADPH:quinine oxidoreductase (NQO-1) in rats following fluid percussion injury. Methods      Traumatic brain injury (TBI) model in rats was established by fluid percussion injury (n=56). At 1

6

12 and 24 h

and 3 and 7 d after operation

the water content in brain tissues was quantified by dry-wet measurement

and the protein expression levels of Nrf2 (cytoplasm and nuclear)

NO-1 and NQO-1 were detected by Western blotting. Also

the mRNA expression of Nrf2 was measured by real-time (RT) PCR.    Results     Comparing with normal control (NC) group

the water content in TBI group increased after 6 h

reaching the peak at 24 h and retaining for 3 d

and then dropped (P0.05). This was in agreement with the edema tendency in injured brain tissue observed by pathohistological staining. Moreover

Western blotting result showed the same change trend in protein expression of Nrf2 in nuclei

NO-1 and NQO-1 but not Nrf2 in cytoplasm. Only after 7 d

their expression was remarkably decreased but still higher than NC group (P0.05). The expression of Nrf2 in cytoplasm was consistently decreased after 12h of the injury. In addition

RT-PCR analysis showed that there were no significant differences in Nrf2 mRNA levels in TBI group at different time points (P0.05).  Conclusion      Nrf2 is translocated and activated in rats following fluid percussion injury

indicating that Nrf2-ARE signaling pathway may be involved in neuro-protection via upregulating expression of NO-1 and NQO-1 proteins in TBI.