In vivo and in vitro effects of flutamide and diethylstilbestrol on fetal testicular steroidogenesis in the rat

Prenatal testosterone surge is considered crucial for physiological masculinization of male progeny. Disorders in sex steroid hormone balance during the fetal development may interfere with male reproductive health later in life. In this study, we have investigated in utero and in vitro effects of flutamide (FLU) and diethylstilbestrol (DES) on fetal rat testicular steroidogenesis. In utero exposure to FLU 25 mg/kg or DES 0.02 mg/kg had no obvious effects on ED 19.5 rat testicular testosterone and progesterone production, StAR protein or AR protein expression. However, when ED 19.5 rat testis were cultured for 180 min in the presence of 0.1, 1, 10 and 100 mg/l of FLU or DES, the highest doses of both compounds were capable of disturbing steroidogenesis. To study the rate of the changes seen in testicular steroidogenesis after 180 min, time-series experiments, in which intact testes were cultured with FLU 100 mg/l or DES 100 mg/l for 30, 60 or 120 min, were performed. In vitro time-series experiments revealed that changes in steroidogenesis occur very fast. Experiments with FLU brought further evidence to the hypothesis that ARs have negative autocrine role in developing Leydig cells.