Effects of nimodipine and magnesium sulfate on endogenous antioxidant levels in brain tissue after experimental head trauma

To examine the effects of calcium antagonists nimodipine and magnesium sulfate (MgSO4) on tissue endogenous antioxidant levels, the authors studied superoxide dismutase (SOD) and glutathione peroxidase (GPx) levels in rabbit brain 1 hour after experimental head trauma. Forty New Zealand rabbits were anesthetized and randomly divided into four groups. Group 1 (n = 10) was the sham operated group. Group 2 (n = 10), the control group, received head trauma and no treatment. Group 3 (n = 10) received head trauma and intravenous (IV) 2 μgr/kg nimodipine. Group 4 (n = 10) received head trauma and IV 100 mg/kg MgSO4. Head trauma was delivered by performing a craniectomy over the right hemisphere and dropping a weight of 20 g from a height of 40 cm. In the right (traumatized) hemisphere, SOD and GPx decreased by 57.60% ± 9.60% and 72.93% ± 5.51% respectively from sham values. Magnesium sulfate, but not nimodipine, reduced the magnitude of decrease of SOD and GPx to 19.43% ± 7.15% and 39.01% ± 7.92% respectively from sham values. In the left (non-traumatized) hemisphere, MgSO4 increased SOD to 42.43% ± 24.76% above sham values. The authors conclude that MgSO4 treatment inhibited the decrease in SOD and GPx levels in experimental brain injury.