A simple technique for the estimation of regional blood content in brain

A simple and inexpensive technique is described for the assessment of regional cerebral blood volume (CBV) using a color reaction based on the pseudoperoxidase activity of hemoglobin. Cryostat sections are placed on a commercially available reagent strip originally designed for quantitative estimation of blood content in urine. After melting of the brain section, a blue color reaction appears which is darker in areas with higher hemoglobin content. The image is analyzed by a computerized image-processing system and evaluated by standards prepared from brain homogenate with different hemoglobin content. From the optical density data, regional CBV is calculated with correction for the difference between microvascular and large vessel hematocrit. The method was validated by a radiolabel procedure. Values of regional CBV are reported in gray matter areas of control rabbits and in brains embolized by autologous clot. This simple inexpensive technique is a useful supplementary tool in multiparametric metabolic studies.