An improved method for the preparation of rat brain microsomes.

The rat brains homogenized with different media (sucrose, ethylene glycol, dimethyl sulfoxide and urea) yielded different amounts of microsomal fractions. The dielectric constant, density and viscosity of the homogenization media did not correlate with the amount of microsomes separated by differential centrifugation. The homogenization media containing dimethyl sulfoxide were the most efficient for the isolation of rat brain microsomes. The increase in the yield was up to 4-fold when 50% (v/v) dimethyl sulfoxide was employed. Microsomes isolated in this manner were analogous to those obtained from isotonic sucrose solution, as was demonstrated by their chemical and enzymatic (5'-nucleotidase, adenosine deaminase, guanine deaminase, purine-nucleoside phosphorylase, lactate, malate and glutamate dehydrogenases, amine oxidase fumarate hydratase, acid and alkaline phosphatase, acetylcholinesterase, NADPH-cytochrome c reductase, catalase and thiamine-diphosphatase) characterization.