Effect of sodium molybdate on the interaction of androgens and progestins with binding proteins in human hyperplastic...

A reliable measurement of steroid hormone receptors is essential for attempts to correlate receptor levels with response to endocrine therapy in prostatic carcinoma. Evidence that receptors in many tissues are stabilized by sodium molybdate prompted the examination of the effects of this salt on the measurement of steroid-binding sites in human prostatic tissue. The presence of molybdate (10 mmol/l) during tissue homogenization, cytosol or nuclear extract preparation and binding-site assay led to a threefold increase in the amount of high-affinity androgen binding detected in cytosol, and a slight increase in the number of cytosol progestin-binding sites. The apparent binding affinity for steroids was increased in both cases. No effect of molybdate was observed on androgen-binding sites in nuclear extracts.