TIME-LEVEL RELATIONSHIP FOR LIPID-PEROXIDATION AND THE PROTECTIVE EFFECT OF ALPHA-TOCOPHEROL IN EXPERIMENTAL MILD AND SEVERE BRAIN INJURY

OBJECTIVE: Oxygen free radical-mediated lipid peroxidation has been pr oposed to be one of the major mechanisms of secondary damage in trauma tic brain injury. The first purpose of this study was to establish the time-level relationship for lipid peroxidation in injured brain tissu e. The second purpose was to examine the protective effect of alpha-to copherol against lipid peroxidation. METHODS: For this study, 65 guine a pigs in five groups were studied. Five of the animals were identifie d as a control group, and the remaining 60 animals were divided equall y into four groups (Groups A, B, C, and D). Mild injury (200 g x cm) ( Groups A and C) and severe injury (1000 g x cm) (Croups B and D) were produced by the method of Feeney et al. alpha-Tocopherol (100 mg/kg) w as administered intraperitoneally before brain injury in Groups C and D, Five animals from each group were killed immediately after trauma, five after 1 hour, and the remaining five animals after 36 hours. Lipi d peroxidation in traumatized brain tissues was assessed using the thi obarbituric acid method. RESULTS: In all groups with traumatic brain i njuries, levels of malondialdehyde, a lipid peroxidation product, were higher than in the control group. The amount of lipid peroxidation wa s increased by the severity of the trauma. alpha-Tocopherol significan tly suppressed the rise in lipid peroxide levels in traumatized brain tissues. CONCLUSION: This study demonstrates that lipid peroxidation i s increased by the severity of trauma and that cy-tocopherol has a pro tective effect against oxygen free radical-mediated lipid peroxidation in mild and severe brain injury.