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A steroid that serves as an intermediate in the biosynthesis of numerous hormones, including progesterone. Serum levels are elevated in a rare form of congenital adrenal hyperplasia.


/preg·ne·no·lone/ (preg-nēn´ŏ-lōn) an intermediate in steroid hormone synthesis.

pregnenolone (preg·neˑ·n·lōn),

n a precursor to steroid hormones that is synthesized (endogenously) from cholesterol or (exogenously) from soybeans. Has been used in a host of conditions including Alzheimer's disease, menopausal complaints, Parkinson's disease, osteoporosis, fatigue, stress, memory loss, and other conditions. May interact with the use of supplemental steroid hormones.


a precursor in the synthesis of steroid hormones, formed from cholesterol.
References in periodicals archive ?
The finding suggests that the steroid, pregnenolone sulfate, may target a specific receptor in the brain and may also be useful in treating people with memory difficulties.
In the present study, P450scc expression in Leydig cells was up-regulated after exposure to B[alpha]P (Figures 5, 6); this appears to be associated with a compensatory phenomenon related to producing the maximal amount of pregnenolone with a minimal amount of transported cholesterol by the reduced StAR content, but the association remains uncertain at present.
Automated chromatographic system for the simultaneous measurement of plasma pregnenolone and 17-hydroxypregnenolone by radioimmunoassay.
As part of his adaptive homeostat protocol, Dean recommends 10 to 100 mg of pregnenolone per day, taken in the morning.
Biosynthesis of endogenous ouabain from pregnenolone and progesterone in bovine adrenal cortical cells.
38) for OLF, but do not at this time exclude pregnenolone as a precursor.
One option for patients deficient in both is pregnenolone, dosed between 25 and 100 mg per day.
4 46 S76489 Estrogen sulfotransferase 20 43 isoform 3 K00996 Cytochrome P450e 11 13 (phenobarbital-induced) M13646 Pregnenolone 16-alpha- 3.
Similarly, other work has shown that the use of both progesterone and pregnenolone as precursors in the biosynthetic pathway noticeably increased the secretion of OLF in adrenal cells, but that cortisol as a precursor only slightly increased OLF secretion into the medium (40).
77-85) Hormones originate in the mitochondria where cholesterol is converted to pregnenolone, the precursor to all steroid hormones.
Rifampicin (RIF) and pregnenolone 16[alpha]-carbonitrile (PCN) were purchased from BioMol (Plymouth Meeting, PA).