[Testosterone metabolism in discrete areas of the brain in rat fetuses]

Experiments in vitro with further thin-layer chromatography of steroids were staged to investigate changing of 3H-testosterone into 3H-estradiol-17 beta and 3H-5 alpha-reduced metabolites in a fraction of 1000 g of homogenates of the medial preoptic area (MPA), the paraventricular nuclei (PVN), the dorsal vagal complex (DVC) of the lower cerebral trunk, the rostral and caudal parts of the amygdaloid complex (ACr and ACc) of the brain of 21-day male and female rat fetuses. The activity of aromatase (AA) and 5 alpha-reductase (AR) was detected in all investigated areas. AA was maximum in PVN of females and minimum in ACc of males and females. The production of 5 alpha-dehydrotestosterone prevailed among 5 alpha-reduced products in PVN, DVC and ACr, 5 alpha- and rostane-3 alpha and 17 beta-diol--in MPA and ACr, AR in ACr was much higher than in ACc. AR in DVC of females was slightly higher than in males. Sex differences in the other cerebral areas were undetectable. The results of the investigation suggest that the above cerebral structures are dependent on sex hormones.