Binding of Cyproterone Acetate to Plasma Proteins 1

Abstract

Summary

Cyproterone acetate (CA), a potent antiandrogen with progestational properties, was tested for binding affinity against sex hormone-binding globulin (SHBG) and corticosteroid-binding globulin (CBG). CA readily displaced 3 H-testosterone but not 3 H-estradiol-17β from SHBG indicating the possibility of more than one binding site on SHBG. CA did not displace 3 H-corticosterone from CBG. CA thus behaves as a C₁₉ rather than a C₂₁ steroid in binding to plasma proteins.