Development of human fetal prostate in culture.

The direct influence of androgens on prostatic development was studied by culturing explants of urogenital sinuses of human embryos and fetuses aged 6 to 13 weeks in the presence of either (10(-7) mol/l testosterone or dihydrotestosterone for 6 days. The differentiation of prostatic epithelial cells started both in control and androgen-treated explants in the ninth week, and androgens accelerated the differentiation of the secretory pathway organelles in the epithelial cells. The amount of granular endoplasmic reticulum and the number of Golgi complexes increased in the presence of androgens, especially in the older fetuses. Incipient secretory activity appeared in some cells during the culture and the differentiation occurred sooner in the androgen-treated explants than in the controls or in vivo. The differentiation and maintenance of the urogenital mesenchyme was also better in the presence of the hormone. The direct epitheliomesenchymal cell contacts seen earlier in vivo were also seen during the differentiation in vitro. These contacts may indicate an inductive role of the mesenchyme in the glandular morphogenesis. Androgens were not able to induce the epithelial differentiation in vitro before the first signs of mesenchymal differentiation were evident in vivo. The results suggest either that the mesenchymal changes are not solely determined by androgens or that the early explants may require additional factors for proper differentiation.