Androgens and the androgen receptor (AR) are indispensable for expression of the male phenotype. The two most important androgens are testosterone and 5α-dihydrotestosterone. The elucidation of the mechanism of androgen action has a long history starting in the 19th century with the classical experiments by Brown-Séquard. In the 1960s the steroid hormone receptor concept was established and the...

Studies from this laboratory have shown that renal N-nitrosodimethylamine demethylase (NDMA demethylase), an enzyme responsible for the metabolism of NDMA, shows age- and sex-related differences and is modulated by testosterone. These results have been positively correlated with NDMA-induced mutagenicity and carcinogenicity studies; however, relatively large doses of testosterone (100 mg/kg or ...

1. A comparison was made of the binding of 5alpha-dihydrotestosterone (17beta-hydroxy-5alpha-androstan-3-one) and cyclic AMP in the rat prostate gland. Distinct binding mechanisms exist for these compounds, and cyclic AMP cannot serve as a competitor for the 5alpha-dihydrotestosterone-binding sites and vice versa. In contrast with the results obtained with 5alpha-dihydrotestosterone, very small...

The rat prostate carcinoma (Dunning R-3327) contains a relatively high concentration of androgen receptor (80 to 150 fmol/mg cytosol protein). We characterized this receptor for comparison with androgen receptors in normal organs of the rat. Binding of testosterone and dihydrotestosterone was of high affinity (Ka = 2 X 10(9) M). Rates of dissociation were slow (t 1/2 testosterone = 60 hr; t 1/2...

Plasma testosterone, dihydrotestosterone, androstenedione, dehydroepiandrosterone sulfate, androsterone and epiandrosterone sulfates, cortisol and sex hormone binding globulin were measured in six adult men before and during daily isoflavone extract ingestion (40 mg) in the form of Trinovin tablets. Although modest plasma genistein levels were achieved following three weeks of Trinovin ingestio...

It has been known that estrogen has synergistic effects with androgen on growth of normal male accessory sex organs of rats. The present study was therefore undertaken to examine the effects of estrogen on androgen-responsive rat Dunning R 3327 prostatic tumor. The weight of male accessory sex organs was suppressed by estrogen on growth of treatment, but synergistic effects of estrogen and andr...

Testosterone estradiol-binding globulin (rbTeBG) of rabbit plasma was purified to homogeneity by the sequential use of ammonium sulfate precipitation, affinity chromatography on 5a-dihydrotestosterone-Sepharose, reactive blue-Sepharose, and finally preparative polyacrylamide gel electrophoresis. An overall purification of greater than 3000-fold was achieved with a recovery of 32%. This purified...

OBJECTIVE The potential role for the gonadal steroids in the pathogenesis of urolithiasis, higher mean of plasma oxalate concentration and kidney calcium oxalate deposition influenced by androgens in men has been proposed. In this study, the serum levels of steroid hormones as a pathogenesis of this condition in male patients with active renal stone disease compared with controls was investigat...

The skin is an endocrine organ with the expression of metabolizing enzymes and hormone receptors for diverse hormones. The sebaceous gland is the main site of hormone biosynthesis, especially for androgens, and acne is the classical androgen-mediated dermatosis. In sebocytes, conversion of 17-hydroxyprogesterone directly to dihydrotestosterone bypassing testosterone has been demonstrated, while...