Androgen Binding to Cytosol and Nuclei of Hamster Sebaceous Glands

The study demonstrated specific dihydrotestosterone (DHT) binding in the cytosol and nuclei of hamster sebaceous glands. In the cytosol, a high-affinity binding peak for DHT was observed at the 7–8S region, with a dissociation constant (KD) of 1.5 × 10−9 M. Testosterone also bound in this region but to a lesser extent. Various steroids competed for binding, with DHT showing the highest affinity. In the nuclei, three peaks of radioactivity were observed, with the second peak indicating specific DHT binding, which was saturable and could be inhibited by excess unlabeled DHT and cyproterone acetate. The formation of the DHT-macromolecule complex in the nuclei required cytoplasmic factors.