Dihydrotestosterone prevents glucocorticoid-negative effects on fetal rat metatarsal bone in vitro

The effects of dihydrotestosterone (DHT) on glucocorticoid-pretreated fetal rat long bone were studied in an in vitro culture system. First, dose-response curves of corticosterone, hydrocortisone, and dexamethasone were studied at several concentrations. Then, hydrocortisone (H) at 10(-5) M was selected for the second part of the study, as it slackened rudiment mineralization (104 +/- 16% of the initial dark zone vs. 141 +/- 9% in control bones), as well as its lengthening (140 +/- 4% of the harvesting day length vs. 160 +/- 1% in control bones), by both inhibition of cell proliferation and stimulation of resorption. On the contrary, in H-pretreated metatarsal bones, DHT (10(-7) M) partly limited slackening of mineralization (124 +/- 5%) and lengthening (153 +/- 2%). Moreover, a control-like cell proliferation was re-established and resorption holes were filled in. Thus, in this study, DHT partly limited hydrocortisone-induced impairment of fetal rat metatarsal bone development.