Specific binding of [ 3H]-methyltrienolone to both progestin and androgen binding components in human benign prostatic hypertrophy (BPH)

Abstract

As previously reported. [ 3H]-R1881, a stable tracer having high affinity for both androgenic and progestin binding components, binds to BPH cytosol with a predominant progestin-like specificity. However, when incubation was performed in the presence of a large excess of triamcinolone acetonide, a typical androgen binding specificity was demonstrated. This is explained by masking of the progestin binding component by triamcinolone acetonide, a steroid which has high affinity for the progestin receptor and no affinity for the androgen binding component. The present data clearly show that [ 3H]-R1881, in the presence of triamcinolone acetonide, can be efficiently used for determination of androgen binding in BPH, a tissue which contains both androgen and progestin binding components. A similar approach could be adopted for other tissues containing these two receptors.