Effects of magnesium sulfate on tissue lactate and malondialdehyde levels in experimental head trauma

To determine the effects of magnesium sulfate (MgSO4) on tissue lactate and malondialdehyde (MDA) levels in rabbit brain after experimental head trauma. Prospective, randomized trial. Thirty New Zealand rabbits. Group 1 (n = 10) was the sham operated group. Group 2 (n = 10) (untreated group) and group 3 (n = 10) received head trauma with the weight drop method. MgSO4 was administered 100 mg/kg (15 %) i. v. immediately after the head trauma to group 3. Trauma was applied to one side. The non-contused side was named as "a" and the contused side as "b". One hour after trauma, brain cortices were resected and the concentrations of lactate and MDA were determined using the spectrophotometric enzymatic and thiobarbituric acid methods. One-way ANOVA and Tukey's HSD tests were used for the evaluation of the results. P < 0.05 was considered as significant. Pearson's correlation test was used between lactate and MDA levels (P < 0.001). There were significant differences between MDA and lactate levels of group 1 and all other groups; non-contused (a) and contused (b) sides of groups 2 and 3; groups 2b-3a, 2b-3b (P < 0.05). The difference in MDA levels was significant between groups 2a-3b (P < 0.05). Correlation between lactate and MDA was very good in group 1, and excellent in groups 2a, 2b, 3a, and 3b. These results demonstrate that head trauma leads to an increase in brain tissue lactate and MDA levels, and MgSO4 suppresses the rise in contused tissue when given after head trauma.