Simple quantitative evaluation of blood-brain barrier disruption in vasogenic brain edema

Traumatic damage to the brain results in blood-brain barrier disruption with subsequent formation of vasogenic brain edema. The goal of this study was to evaluate a colorimetric assay of Evans blue extravasation for quantitatively studying blood-brain barrier disruption. Vasogenic brain edema was produced by a cortical freezing lesion. 52 male Wistar rats were sacrificed and cardiac perfusion was performed. A volume of dimethylformamide, twice the brain weight, was added to the brain and this was incubated for 72 hours. The supernatant was analyzed spectrophotometrically. Evans blue contents in the lesioned hemisphere was significantly increased within one hour after the lesion production relative to the normal brain and continued to increase for 24 hours (p < 0.01). This quantitative assay of Evans blue is a simple method for evaluation of blood-brain barrier disruption in vasogenic brain edema.