While maintaining the actual conditions prevailing in benign prostatic hyperplasia (BPH) in man, transplantation of BPH tissue to newborn rats proved a suitable model for examining the distribution of sexual hormones in different tissue compartments of BPH. In combination with the microautoradiographic method, it was possible to demonstrate the residence of the radioactive androgen 5α-dihydrotestosterone (5α-DHT), the antiandrogen cyproterone acetate (CA) and the oestrogen oestradiol-17β (E2) in the epithelium and/or stroma of human BPH tissue. Quantitative evaluation in the form of a point per area count on photographic pictures yielded a silver grain distribution ratio in epithelium and stroma of 1.3:1 and 1.5:1 for epithelium to stroma after administration of [3H]5α-DHT and [3H]CA administration respectively and 0.5:1 after [3H]E2.
The high tracer recovery rate throughout the stroma following E2 administration supports the current view that the stromal proliferation is attributable mainly to oestrogen influences.
The relatively high silver particle proportion throughout the stroma following 5α-DHT administration corroborates recent findings which suggest that the exclusive androgen dependency of the glandular epithelium can only be considered in conjunction with an active metabolization of androgens in the stroma.
The correspondence in the distribution of the radioactive tracer after [3H]5α-DHT and [3H]CA administration both in the epithelium and stroma suggests that an antagonism may also exist in the stroma.