A QUANTITATIVE METHOD FOR THE MEASUREMENT OF INCREASED VASCULAR PERMEABILITY

A method is described for the extraction and determination of pontamine blue exuded in the skin of rabbits, in order to measure increased vascular permeability to protein. It involves four procedures, viz., (1) homogenization of the skin treated with hot trichloroacetic acid solution, (2) precipitation of gelatinized collagen with phosphotungstic acid, (3) lipid extraction with ethanol and (4) elution of the dye adsorbed to protein with aqueous pyridine and its spectrophotometric determination. Its successful application to the skin response, induced by histamine, indicates that the method can be used for the quantitative study of substances that affect vascular permeability.