Blocking estrogen synthesis

Aromatase inhibitors that inhibit the androgen aromatization in estrogens and thus block estrogen synthesis. 

Santen RJ (2002) To block estrogen s synthesis or action That is the question. J Clin Endocrinol Metab 87(7) 3007-3012... 

Letrozole and anastrozole are called aromatase inhibitors because they block the activity of the aromatase enzyme, which is responsible for estrogen synthesis. This inhibits tumor growth in those forms of breast cancer that are stimulated by estrogen. 

Certain breast cancers require estrogen to grow. Aromatase inhibitors, because they block the synthesis of estrogen, are a new class of drugs used in the treatment of breast cancer in postmenopausal women. 

Aminoglutethimide blocks the conversion of androgens to estrogens and decreases the synthesis of glucocorticoids. 

INDEPENDENT OF CELL TYPE OF THE ESTROGEN-DEPENDENT GENE THE SYNTHESIS OF messenger-RNA BECOMES BLOCKED... 

FIGURE 12.1 Biosynthesis of estrogens. Abbreviations DHEA, dehydroepiandrosterone El, estrone E2, estradiol T, testosterone DHT, dihydrotestosterone. Letrozole is an aroma-tase inhibitor, Finasteride is a 5a-reductase inhibitor. Androstane-3p,17P-diol (SPO) is an estrogenic steroid and its synthesis is blocked by 5a-reductase inhibitor, but not affected by aromatase inhibitor."... 

---