Oxygen free radicals may contribute to tissue injury processes in the central nervous system following
ischemia or
trauma. Recent studies have suggested that inhibition of
free radicals improves the outcome in experimental models involving such conditions, and
antioxidant therapy appears promising. In the present study, behavioral changes and
edema formation in rat
cortical contusion model were investigated, and the effects of a
superoxide radical scavenger,
OPC-14117, were tested. Wistar rats were anesthetized with
halothane inhalation.
Cortical contusion was induced in the parietal cortex employing a controlled cortical impact device. Immediately following injury induction,
OPC-14117 was administered (300 mg/kg, p.o.).
Edema formation was assessed in the center and peripheral areas of the
contusion by the specific gravity method. Behavioral changes were evaluated by the Morris water maze test and the habituation of exploratory activity. The results revealed that the vehicle-administered control showed progressive
edema formation and behavioral deficits following the injury. These changes were significantly attenuated by the
OPC-14117 treatment (p < 0.05). Further,
OPC-14117 reduced the size of contusional
necrosis (p < 0.05). These findings suggest that
superoxide free radicals are involved in
contusion-induced
edema formation,
necrosis formation, and behavioral deficits, and that
OPC-14117 has a therapeutic potential to prevent secondary cell damage following
traumatic brain injury.