A comparative longitudinal study on sex hormone binding globulin capacity during estrogen replacement therapy.

An aqueous two-phase equilibrium partition system was used to assay SHBG-binding capacity. Sera from groups of postmenopausal women before and during unopposed estrogen replacement therapy were analyzed. The induction of SHBG showed considerable differences between different estrogens. Ethinyl-estradiol in a daily dose of 0.05 mg gave a 70% increase in the serum concentration of this liver derived protein. Estradiol-17 beta, 2 mg daily and estrone sulphate 1.25 mg gave moderate changes, whereas estriol in different doses had no effect. SHBG induction may reflect estrogen overtreatment.