Molecular control of rabbit follicular testosterone production: Role of cyclic AMP and cyclic GMP

Isolated rabbit follicles were incubated with various test substances and labelled uridine, leucine or aminoacid mixture. Cyclic adenosine-3',5'-monophosphate (AMP, 5mM) increased testosterone accumulation by 15 min whereas [3H]-leucine incorporation into protein was elevated by 60 min. Puromycin (1 and 10 μg/ml) and cycloheximide (1 μg/ml) severely inhibited protein synthesis by 45–77%, yet cyclic AMP enhanced testosterone production was not affected by these concentrations of inhibitors. Theophylline and 3-isobutyl-1-methylxanthine (MIX) inhibited both protein and ribonucleic acid (RNA) synthesis but did not influence cyclic AMP enhanced testosterone production, except at 5mM MIX which inhibited testosterone. Actinomycin D severely inhibited RNA synthesis yet had no apparent effect on cyclic AMP enhanced testosterone production. RNA synthesis was consistently stimulated in the presence of cyclic guanosine-3',5'-monophosphate (GMP) which had no effect on protein or testosterone. These results lend further support to our hypothesis of a possible non-obligatory role for protein and strongly suggest that RNA synthesis is not involved in short-term testosterone production by the rabbit follicle.