Androgen Binding in Cytosols and Nuclei of Human Benign Hyperplastic Prostatic Tissue

Abstract

Androgen binding sites have been detected in cytosols and nuclear extracts from human benign hyperplastic prostatic (BPH) tissue with exchange assays using [3H]methyltrienolone and [3H]5alpha-dihydrotestosterone respectively. The concentrations of binding sites and the equilibrium dissociation constants for the [3H]steroid-receptor interactions have been determined and the specificity of the binding has been examined. The observed properties of the binding sites are consistent with those characteristic of androgen receptors. The binding sites are present in nuclear extracts from all BPH tissue samples examined to date. The amount of binding detected in the nuclear fraction is higher than that found in the cytosol.

Relations between Circulating Levels of Testosterone, 17β-Estradiol, Androstenedione, Dehydroepiandrosterone Sulfate, and Androgenic Receptor Content of Cytosol in Benign Prostatic Hyperplasia

“…29, 31], or to incubate the samples at 15 °C to promote inactivation of the pro gesterone receptors [24], Promegestone (R 5020), the competitor used in our studies, has been described as a substance which partially blocks specific binding of methyltrienolone to androgenic receptors [24], thus pro ducing an understimation of Bmax. Nonetheless, the val ues we obtained for the apparent total receptor concentra tion are quite similar to those shown by other authors who used triancinolone acetonide as a competitor [26], or who inactivated progesterone receptors by incubation at 15 °C [24,32]. They are also similar to the mean values of other author's results recently reviewed by Rennie and Bruchovsky [29], which were 160 fmol/g of tissue or 38 fmol/mg of cytosol protein.…”

Cultured human skin fibroblasts: a model for the study of androgen action

“…I I). R1881 has also been reported to bind to the progestin receptor (56)(57)(58)(59), however, we observed no effect of added progesterone on the saturation kinetics of R1881 binding in skin fibroblasts. This finding also implies that genital skin fibroblasts do not contain a progestin receptor.…”

Testosterone

“…We and others noted that the binding characteristics are remarkably similar to those for the cytosolic androgen receptor in the rat prostate (Mainwaring and Milroy 1973;Krieg et al 1980). In addition, other research groups have demonstrated nuclear androgen receptors in BPH which also appear to be similar to those for the rat prostate nuclei (Davies and Griffiths 1975;Menon et al 1978;Sirett and Grant 1978;Symes et al 1978;Lieskovsky and Bruchovsky 1979).…”