Oxidative DNA lesions in a rodent model of traumatic brain injury

Background: Oxidative DNA lesions have not been well studied in traumatic brain injury (TBI). Methods: TBI was induced with a controlled cortical impact injury in rats. Brain tissue was examined for 8-hydroxy-2′-deoxyguanosine (oh8dG) using monoclonal antibodies at different time frames; 15 minutes (n = 4), 30 minutes (n = 7), 60 minutes (n = 6), and 240 minutes (n = 5). The control group consisted of sham-operated animals undergoing the same surgery without the controlled cortical impact injury (n = 5). Results: An elevation of oh8dg was detected in the nuclear and perinuclear (mitochondrial) regions of the ipsilateral cortex, but seldom in those of the contralateral cortex. The amount of oh8dG in those animals with TBI was significant in all time frames when compared with sham-operated controls (p < 0.001). The oh8dG levels were more prominent at 15 minutes (p < 0.0001) when compared with controls. Conclusion: Oxidative DNA lesions occurred in this model of TBI maximally early after TBI. This suggests that oh8dGs may affect genetic material of the brain and that oh8dGs may adversely affect gene expression that occurs early after head injury.