Effect of testosterone on the androgen receptor in the liver cytosol and nuclei of castrated male rats.

The androgen-binding sites in the cytosol and nuclei were decreased 1 week following castration and this reduced level was sustained for 2 weeks. A maximal increase of the androgen-binding sites in the cytosol was induced by a single injection of testosterone, while the sites in the nuclei were increased gradually with the duration of testosterone injection. These findings suggest that testosterone was able to induce the binding sites in the liver cytosol and nuclei which had been reduced after castration.