Estrogen synthesis

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

Fiorelli, G. Picariello, L. Martineti, V. Tonelli, F. Brandi, M. L. Estrogen synthesis in human colon cancer epithelial cells. J. Steroid Biochem. Mol. Biol. 1999, 71, 223-230. 

Anastrozole, a selective nonsteroidal inhibitor of aromatase (the enzyme required for estrogen synthesis. Figures 40-2 and 40-5), is effective in some women whose breast tumors have become resistant to tamoxifen (see Chapter 54). Letrozole is similar. Exemestane, a steroid molecule, is an irreversible inhibitor of aromatase. Like anastrozole and letrozole, it is approved for use in women with advanced breast cancer (see Chapter 54). 

Ovary follicle development, ovulation, estrogen synthesis testis spermatogenesis... 

Follicle-stimulating hormone (FSH] Female t follicular development and estrogen synthesis Male enhance spermatogenesis... 

The prototypical steroidal inhibitor of aromatase (the enzyme required for estrogen synthesis) is testolactone. It is a weak inhibitor of the enzyme, and large quantities need to be administered to achieve clinical effect. 

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. 

The incidence of breast cancer is reduced in immuno-suppressed women. Because cytokine production is also reduced in immunosuppressed women, this finding supports the concept that cytokines have an important role in breast cancer, possibly acting via stimulation of estrogen synthesis. ... 

Purohit A, Newman SP, Reed MJ. The role of cytokines in regulating estrogen synthesis implications for the etiology of breast cancer. Breast Cancer Res 2002 4 65-9. 

Estrogen is a primary promoter of prolactin release. Of course there are other factors to consider (which we will discuss in a moment) that may trigger excessive prolactin secretion, but the normal trend toward increased prolactin release is due to increased estrogen synthesis. 

The body synthesizes all of our manly androgens including testosterone from fat. In fact several studies have documented that diets containing less than 10% fat can significantly decrease a male s androgen production and increase estrogen synthesis. In most cases a diet that provides a minimum of 20% of its calories from fat will also augment a male s total and free testosterone production. 

Mode of action aromatase inhibitor —>1 estrogen synthesis... 

I The clinical uses of anastrozole (decreases estrogen synthesis), danazol (decreases ovarian steroid j synthesis), domiphene (decreases feedback inhibition), and the selective estrogen-receptor modulators j tamoxifen and raloxifene are considered. 

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