We used both in vitro and in vivo approaches to investigate the involvement of RA in the regulation of steroidogenesis in the rat fetal testis. When using the organotypic culture, a validated in vitro approach, RA reduced both basal and acute LH-stimulated testosterone secretion in 14.5- (Fig. 1), 15.5- (Fig. 8), and 16.5- (Figs. 1 […]

In Vitro Experiments Ontogenesis of the effect of RA on basal and acute LH-stimulated testosterone secretion in the rat fetal and neonatal testis. Testes were removed from fetuses on Days 14.5, 16.5, 18.5, and 20.5 postconception and from neonates on Day 3 after birth. They were cultured for 3 days in the absence of LH, […]

Animals Female Sprague-Dawley rats from Charles River (Saint Aubin Les El-beuf, France) were housed in controlled photoperiod conditions (lights-on from 0600 to 0800 h) and fed commercial diets (U.A.R., Villemoisson sur Orge, France) with tap water ad libitum. Males were caged with females for the night. The day following an overnight mating was counted as […]

The fetal and neonatal development of the testis from the sexually undifferentiated genital ridge involves a succession of well-characterized events affecting each testicular cell type (reviewed in and ). Leydig cell function, in particular, develops early in fetal life. Leydig cells differentiate from mesenchymal cells in the interstitial compartment. In the rat, the fetal testis […]