Estrogen metabolism by primary cultures of rat ventral prostate epithelial and stromal cells

Abstract Estrogen metabolism was examined in primary cultures of rat ventral prostate epithelial and stromal cells developed from young (~3 weeks old) animals. Supraphysiologic concentrations (50 nM) of tritium-labelled estradiol (E 2 ) and estrone (E 1 ) were incubated separately with each cell type and the metabolites formed were measured at selected time points over a 24 h period. The metabolites were analyzed using high performance liquid chromatography. Epithelial cells exhibited an equal capability to interconvert E 2 and E 1 thus demonstrating the presence of similar oxidative and reductive activities for 17β-hydroxysteroid oxidoreductase (17β-HSOR) [0.45 and 0.40 pmol/3 h/μg DNA respectively]. In contrast, stromal cells showed a 6-fold lower rate of oxidation of E 2 to E 1 (0.08 pmol/3 h/μg DNA) but exhibited an approx 5-fold higher rate of reduction of E 1 to E 2 (1.81 pmol/3 h/μg DNA). Estriol (E 3 ) formation from either substrate was not detected in the two cell types. The results demonstrate that rat ventral prostate epithelial cells have similar capabilities to form or remove biologically active E 2 . In contrast, prostate stromal cells exhibited a preferential capability to form and possibly maintain high levels of biologically active E 2 . These findings are discussed with reference to the actions of estrogens on prostate epithelial-stromal cellular interactions.