|Systematic (IUPAC) name|
|Mol. mass||332.48 g/mol|
|Melt. point||268 °C (514 °F)|
|(what is this?)|
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. High levels are also achieved during pregnancy.
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 prohormone for glucocorticosteroids and androstenedione through the activity of 3-hydroxysteroid dehydrogenase.
Measurements of 17-OH-pregnenolone are useful in the diagnosis of certain forms of congenital adrenal hyperplasia. 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.
- 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.
- Matsunaga, M; Ukena, K; Baulieu, EE; Tsutsui, K (2004). "7α-Hydroxypregnenolone acts as a neuronal activator to stimulate locomotor activity of breeding newts by means of the dopaminergic system". Proceedings of the National Academy of Sciences of the United States of America 101 (49): 17282–7. doi:10.1073/pnas.0407176101. PMC 535386. 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