Английская Википедия:20α-Dihydroprogesterone

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20α-Dihydroprogesterone (20α-DHP), also known as 20α-hydroxyprogesterone (20α-OHP), is a naturally occurring, endogenous progestogen.[1][2][3] It is a metabolite of progesterone, formed by the 20α-hydroxysteroid dehydrogenases (20α-HSDs) AKR1C1, AKR1C2, and AKR1C3 and the 17β-hydroxysteroid dehydrogenase (17β-HSD) HSD17B1.[4][5] 20α-DHP can be transformed back into progesterone by 20α-HSDs and by the 17β-HSD HSD17B2.[6][7] HSD17B2 is expressed in the human endometrium and cervix among other tissues.[8][9][10][7] In animal studies, 20α-DHP has been found to be selectively taken up into and retained in target tissues such as the uterus, brain, and skeletal muscle.[6]

20α-DHP has very low affinity for the progesterone receptor and is much less potent as a progestogen in comparison to progesterone, with about one-fifth of the relative progestogenic activity.[1][2][3][11][12][6][13] It has also been found to act as an aromatase inhibitor and to inhibit the production of estrogen in breast tissue in vitro.[14]

A single 200-mg oral dose of micronized progesterone has been found to result in peak levels of 20α-DHP of around 1 ng/mL after 2 hours.[15] In another study however, peak levels of 20α-DHP were around 10 ng/mL during therapy with 300 mg/day oral micronized progesterone.[16] 20α-DHP is formed from progesterone in the liver and in target tissues such as the endometrium.[16] It appears to be more slowly eliminated than progesterone.[16]

Levels of 5α-DHP have been quantified.[17]

See also

References

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Шаблон:Steroid hormones Шаблон:Progesterone receptor modulators