17-Hydroxypregnenolone
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17-Hydroxypregnenolone
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| Systematic (IUPAC) name | |
| 3β,17-dihydroxypregn-5-en-20-one | |
| Identifiers | |
| CAS number | 387-79-1 |
| ATC code | ? |
| PubChem | 3032570 |
| Chemical data | |
| Formula | C21H32O3 |
| Mol. weight | 332.48 |
| Physical data | |
| Melt. point | 268 °C (514 °F) |
| Pharmacokinetic data | |
| Bioavailability | ? |
| Metabolism | AdrenalGonads |
| Half life | ? |
| Excretion | ? |
| Therapeutic considerations | |
| Pregnancy cat. |
? |
| Legal status | |
| Routes | ? |
17-Hydroxypregnenolone (also 17-OH-pregnenolone and 17α-hydroxypregnenolone), is a C21 steroid that is obtained by hydroxylation of pregnenolone at the C17α position. This step is performed by the mitochondrial cytochrome P450 enzyme 17α-hydroxylase (CYP17A1) that is present in the adrenal and gonads. Peak levels are reached in humans at the end of puberty and then decline.[1] High levels are also achieved during pregnancy.
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[edit] Prohormone
17-OH-pregnenolone is considered a prohormone in the formation of dehydroepiandrosterone (DHEA), itself a prohomone of the sex steroids.
This conversion is mediated by the enzyme 17,20 lyase . As such 17-OH-pregenolone represents an intermediary in the delta-5-pathway that leads from pregnenolone to DHEA. 17-hydroxypregneolone is also converted to 17-hydroxyprogesterone, a prohomone for glucocorticosteroids and androstenedione through the activity of 3-hydroxysteroid dehydrogenase.
[edit] Neurohormone
There is some evidence that 17-OH-pregnenolone may have activity as a neurohormone.[2]
[edit] Clinical use
Measurements of 17-OH-pregnenolone are useful in the diagnosis of certain forms of congenital adrenal hyperplasia.[3] In patients with congenital adrenal hyperplasia due to 3 beta-hydroxysteroid dehydrogenase deficiency 17-OH-pregnenolone is increased, while in patients with congenital adrenal hyperplasia due to 17 alpha-hydroxylase deficiency levels are low to absent.
[edit] See also
Congenital adrenal hyperplasia
[edit] References
- ^ Hill M, Lukac D, Lapcik O, Sulcova J, Hampl R, Pouzar V, Starka L. Age relationships and sex differences in serum levels of pregnenolone and 17-hydroxypregnenolone in healthy subjects. Clin Chem Lab Med. 1999 Apr;37(4):439-47. PMID 10369116
- ^ Matsunaga M, Ukena K, Baulieu EE, Tsutsui K 7alpha-Hydroxypregnenolone acts as a neuronal activator to stimulate locomotor activity of breeding newts by means of the dopaminergic system. Proc Natl Acad Sci USA 2004 Dec 7;101(49):17282-7. PMID 15569930
- ^ Riepe FG, Mahler P, Sippell, Partsch CJ. Longitudinal Study of Plasma Pregnenolone and 17-Hydroxypregnenolone in Full-Term and Preterm Neonates at Birth and during the Early Neonatal Period. The Journal of Clinical Endocrinology & Metabolism (2002) 87: 4301-4306 [1]
