17α-Hydroxypregnenolone

17α-Hydroxypregnenolone is a pregnane (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.

17α-Hydroxypregnenolone
Pharmacokinetic data
MetabolismAdrenal, Gonads
Identifiers
CAS Number
PubChem CID
ChemSpider
ChEBI
ECHA InfoCard100.006.239
Chemical and physical data
FormulaC21H32O3
Molar mass332.48 g/mol g·mol−1
3D model (JSmol)
Melting point268 °C (514 °F)
 NY (what is this?)  (verify)

Prohormone

17α-Hydroxypregnenolone is considered a prohormone in the formation of dehydroepiandrosterone (DHEA), itself a prohormone of the sex steroids.

This conversion is mediated by the enzyme 17,20 lyase. As such 17α-hydroxypregenolone represents an intermediary in the Δ5 pathway that leads from pregnenolone to DHEA. 17α-Hydroxypregneolone is also converted to 17α-hydroxyprogesterone, a prohormone for glucocorticosteroids and androstenedione through the activity of 3α-hydroxysteroid dehydrogenase.

Clinical use

Measurements of 17α-hydroxypregnenolone are useful in the diagnosis of certain forms of congenital adrenal hyperplasia.[2] In patients with congenital adrenal hyperplasia due to 3β-hydroxysteroid dehydrogenase deficiency 17α-hydroxypregnenolone is increased, while in patients with congenital adrenal hyperplasia due to 17α-hydroxylase deficiency levels are low to absent.

See also

Additional images

References

  1. Hill, M; Lukác, D; Lapcík, O; Sulcová, J; Hampl, R; Pouzar, V; Stárka, L (1999). "Age relationships and sex differences in serum levels of pregnenolone and 17-hydroxypregnenolone in healthy subjects". Clinical chemistry and laboratory medicine : CCLM / FESCC. 37 (4): 439–47. doi:10.1515/CCLM.1999.072. PMID 10369116.
  2. 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 Archived 2011-05-16 at the Wayback Machine
This article is issued from Wikipedia. The text is licensed under Creative Commons - Attribution - Sharealike. Additional terms may apply for the media files.