Progestin biosynthesis

The ovary is the major site of estrogen and progestin biosynthesis in nonpregnant premenopausal women. In pregnant women, the fetoplacental unit is the major... 

The rate-limiting step in progestin biosynthesis is the side-chain cleavage of cholesterol to pregnenolone taking place in the mitochondria. At least three steps in the cholesterol side-chain cleavage (SSC) reaction may be under hormonal regulation [72,73]. FSH stimulates the synthesis of the SSC cytochrome P-450 which results in the stimulation of SSC activity [74]. 

Progeslerone, structure and function of, 1083 Progestin, 1082 function of. 1082 Proline, biosynthesis of, 932... 

High-dose progestins are used as last-line endocrine therapy [223]. They inhibit the adrenal steroid biosynthesis. The decrease of estrogen levels is comparable to that caused by the administration of aromatase inhibitors. In post-menopausal women, the progestin megestrol acetate (MGA) decreases serum plasma level of DEAH, androstenedione and cortisol to less than 10% [223,224]. 

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