EN
The synthesis of estrogens from androgens is catalyzed by an enzyme complex called aromatase, and therefore has a unique potential to influence the physiological balance between the sex steroid hormones. This enzyme complex consists of two components: aromatase cytochrome P450 and NADPH-cytochrome P450 reductase. Aromatase is conserved amongst all vertebrates and mammals in particular. It is a member of the cytochrome P450 super-family of enzymes. Within this, aromatase cytochrome P450 is presently the sole member of family 19, and is encoded by the gene known as CYP19 which contains a number of tissue-specific promoters that direct aromatase expression in different tissues via alternative splicing. A number of tissues in mammals have the capacity to express aromatase. These include the ovaries and testes, the placenta, adipose tissue, osteoblasts of bone, vasculature smooth muscle, and numerous sites in the brain.