Effects of chemical pretreatment on posttraumatic cortical edema in the rat.

The purpose of this study was to evaluate the effects of mannitol (Man), dexamethasone (DM), dichloroacetic acid (DCA) and 1,3-butanediol (BD) in reduction of posttraumatic cortical edema following brain deformation injury to rats. Ten minutes prior to fluid percussion injury, each animal received one of four pretreatments or placebo: Man, 1 g/kg intravenously, DM 3.0 mg/kg intravenously, DCA 25 mg/kg intraperitoneally BD 0.5 mg/kg intraperitoneally (n = 12 per treatment group), or equivolume saline (n = 8 per corresponding trauma group). Six hours after trauma, cortical tissue was harvested. Using a benzene-kerosene gradient column calibrated with potassium sulfate standards, the specific gravity (SpG) of cortical tissue from each group was measured and compared (ANOVA, P < .05). The measured cortical SpG from traumatized animals receiving Man (mean 1.037 +/- SEM .001), DCA (1.038 +/- .001), and BD (1.039 +/- .001) were equal to SpG from untraumitized cortex (1.041 +/- .001), and were significantly greater than SpG from traumatized cortex for animals receiving DM (1.035 +/- .001) or placebo (1.033 +/- .002). Pretreatment with DCA, Man, and BD appears to protect against development of posttraumatic cortical edema when measured 6 hours after blunt head trauma in the rat. Each of these chemical treatments appears effective in preventing or reducing posttraumatic cortical edema.