[Aromatization of androgens (author's transl)].

Aromatization of androgens into estrogens is an early phenomenon during phylogenesis and ontogenesis which occurs in most tissues. The mechanism which is responsible for this activity and for it's competition with 5 alpha reduction includes hypothalamo-pituitary receptors, genetic induction of sexual differentiation, binding proteins, and sulfo and glyco-conjugation. Aromatization is determinant before, during, and after ovulation, as well as in developing pregnancy. In the testis, in spite of it's importance, it's role is unknown. It's action is essential in the sexual differentiation of the brain. Aromatization in the muscle and the adipose tissue is not negligible under normal and pathological conditions.