Neuropharmacological study on the induction of hypothalamic masculinization in female mice

82% of female mice, that had received a single injection of 50 mug testosterone propionate (TP) at 4 days of age, became persistent estrous by 90 days. If 50 mug pentobarbital or 10 mug reserpine was given simultaneously with TP, the incidence of hypothalamic masculinization (persistent estrus (PE) and polyfollicular ovaries lacking corpora lutea) at 90 days dropped to 33 and 30%, respectively. Phenoxybenzamine (50 mug) also decreased the incidence of PE to 20 and 30% at 60 and 90 days of age, respectively. However, propranolol failed to nullify the masculinization caused by TP. These results seem to suggest that a monoaminergic mechanism is involved in the hypothalamic masculinization of neonatal mice.