EFFECTS OF 17-BETA-N,N-DIETHYLCARBAMOYL-4-METHYL-4-AZA-5-ALPHA-ANDROSTAN-3-ONE ON STEROIDOGENESIS IN GONADS OF RAT FETUSES

1. The effect of 5-alpha-reductase inhibitor 17-beta-N,N-diethylcarbamoyl-4-methyl-4-aza-5-alpha-androstan-3-one (4-MA) on the fetal rat steroidogenesis was examined. 18- and 20-day-old fetal ovaries were incubated in the presence of dcAMP (1 mM) and spironolactone (10 mM) and progesterone production was assessed with and without 4-MA (0.01-50-mu-M). 2. High concentrations of 4-MA significantly decreased the production of progesterone. 3. Similar inhibition of the testosterone synthesis was observed in 16-day-old fetal testes explanted either in the control medium (M 199) or in the presence of LH (100 ng/ml) when treated with 4-MA. The effect was rapidly reversible in both gonads.