Study of C19 O2 Steroids in Human Plasma by Competitive Protein Binding

Abstract

This chapter presents the study of C 19 O 2 steroids in human plasma by competitive protein binding. The steroid binding β -globulin is neither specific for testosterone nor for estradiol and binds a number of other steroids, particularly those possessing a 17 β -hydroxyl group. In the present study, the presence of some of these steroids in plasma extracts of normal men and women were studied by means of a competitive protein binding technique. It has been shown that the plasma extracts of normal men and women contain significant amounts of neutral steroids, different from testosterone, which produce a displacing effect in the binding assay. The measurement of testosterone by competitive protein binding to the steroid binding β -globulin should involve a chromatographic purification step.