17α-Hydroxypregn-4-ene-3,20-dione, Hydroxyprogesterone (INN)
3D model (JSmol)
CompTox Dashboard (EPA)
|Molar mass||330.46 g/mol|
Except where otherwise noted, data are given for materials in their standard state (at 25 °C [77 °F], 100 kPa).
17α-Hydroxyprogesterone (17α-OHP), or hydroxyprogesterone (OHP), is an endogenous progestogen steroid hormone related to progesterone. It is also a chemical intermediate in the biosynthesis of many other endogenous steroids, including androgens, estrogens, glucocorticoids, and mineralocorticoids, as well as neurosteroids.
17α-OHP is an agonist of the progesterone receptor (PR) similarly to progesterone, albeit weakly in comparison. In addition, it is an antagonist of the mineralocorticoid receptor (MR) as well as a partial agonist of the glucocorticoid receptor (GR), albeit with very low potency (EC50 >100-fold less relative to cortisol) at the latter site, also similarly to progesterone.
|Notes: Values are percentages (%). Reference ligands (100%) were progesterone for the PR, dexamethasone for the GR, and estradiol for the ER. Sources: See template.|
17α-OHP increases in the third trimester of pregnancy primarily due to fetal adrenal production.
This steroid is primarily produced in the adrenal glands and to some degree in the gonads, specifically the corpus luteum of the ovary. Normal levels are 3-90 ng/dl in children, and in women, 20-100 ng/dl prior to ovulation, and 100-500 ng/dl during the luteal phase.
Measurements of levels of 17α-OHP are useful in the evaluation of patients with suspected congenital adrenal hyperplasia as the typical enzymes that are defective, namely 21-hydroxylase and 11β-hydroxylase, lead to a build-up of 17α-OHP. In contrast, the rare patient with 17α-hydroxylase deficiency will have very low or undetectable levels of 17α-OHP. 17α-OHP levels can also be used to measure contribution of progestational activity of the corpus luteum during pregnancy as progesterone but note, 17α-OHP is also contributed by the placenta.
Earlier immunoassays like RIA (radioimmunoassay) or IRMA (immunoradiometric assay) were used to clinically determine 17α-OHP. Today more sophisticated methods use gas or liquid chromatography and mass spectrometry (e.g. LC-MS/MS).
Esters of 17α-OHP, such as hydroxyprogesterone caproate and, to a far lesser extent, hydroxyprogesterone acetate and hydroxyprogesterone heptanoate, have been used in medicine as progestins. When "hydroxyprogesterone" is referenced from the standpoint of medical use, what is usually being referred to is actually, in general, hydroxyprogesterone caproate.
17α-OHP, also known as 17α-hydroxypregn-4-ene-3,20-dione, is a naturally occurring pregnane steroid. It features ketone groups at the C3 and C20 positions, a hydroxyl group at the C17α position, and a double bond between the C4 and C5 positions.
17α-OHP is the parent compound of a class of progestins referred to as the 17α-hydroxyprogesterone derivatives. Among others, this class of drugs includes chlormadinone acetate, cyproterone acetate, hydroxyprogesterone caproate, medroxyprogesterone acetate, and megestrol acetate.