[The role of testosterone metabolism in the hypothalamus in regulating the gonadotropic function of the hypophysis in male pre- and postpubertal rats].

Experiments were staged on immature (21 days) and mature (3.5 mos.) Wistar male rats to investigate the influence of the aromatase inhibitor 1, 4, 6-androstatriene-3, 17-dione on the activity of the aromatase and 5 alpha-reductase enzymatic complexes of the hypothalamus and the blood levels of LH and testosterone (T). The formation of 5 alpha-dehydrotestosterone against a background of aromatase activity inhibition was increased in mature rats and was unchanged in immature animals. The blood levels of LH and T were increased, the reaction of LH in immature animals being more marked. A conclusion has been made of a role of T aromatic transformations in the hypothalamus in tonic inhibition of LH secretion by endogenous T and a possible involvement of this mechanism in the maturation of male rats.