Androgen dynamics in vitro in the human prostate gland. Effect of oestradiol-17β

Abstract

Normal, hyperplastic and adenocarcinomatous human prostatic tissue was perfused in vitro with radioactively labelled androstenedione, testosterone and 5α-dihydrotestosterone with and without added oestradiol-17β. Various parameters of tissue–steroid relationship were measured at the steady state. When oestradiol (0.11 or 0.22μmol/l) was added to the perfusing medium, the entry of the steroids into the tissue and their metabolism was increased in the majority of the glands studied. The ‘uptake’ of all the steroids varied, in response to the addition of oestradiol, in both normal and adenocarcinomatous glands in a way differing from the response of hyperplastic glands. As a consequence, the tissue clearance of the steroids, particularly of androstenedione and testosterone, increased in normal and adenocarcinomatous glands in the presence of oestradiol, and decreased in the hyperplastic tissues. At a concentration 0.33μmol/l, oestradiol decreased the entry of the steroids in all the tissues studied, while the clearance of steroids tended to decrease. The significance of these findings in terms of the regulation of androgen dynamics in vivo in the normal and diseased human prostate, with particular regard to the response to oestrogen treatment, is discussed.