pregnenolone


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pregnenolone

[preg′nen·ə‚lōn]
(biochemistry)
C21H32O2 A steroid ketone that is formed as an oxidation product of cholesterol, stigmasterol, and certain other steroids.
McGraw-Hill Dictionary of Scientific & Technical Terms, 6E, Copyright © 2003 by The McGraw-Hill Companies, Inc.
References in periodicals archive ?
Therefore, it was perhaps unsurprising that intermediates such as 11-deoxycortisol, 17-hydroxypregenenolone, and pregnenolone provided discrimination of adrenocortical carcinoma from other adrenal lesions using serum (1).
A side chain of cholesterol imported into the mitochondria is cleaved by the action of CYP11A1 to produce pregnenolone. The stimulatory effect of nandrolone on CYP11A1 activity in human placental extract culture has been reported [18].
Serum concentrations of pregnenolone, 17a hydroxyprogesterone, corticosterone, DHEA, and androstenedione were measured by LC-MS method using an Agilent 1200 Series HPLC system for HPLC (Agilent Technologies Inc., California, USA) and an AB Sciex API5000 tandem mass spectrometer (AB Sciex Pte.
The hormone I suspected Audrey was lacking is called pregnenolone. It's sometimes referred to as a prohormone and can be considered the "mother" of all the steroid hormones.
De novo synthesis of all steroid hormones starts with the conversion of cholesterol to pregnenolone by CYP11A (cholesterol side-chain cleavage) [13].
There has been a report, however, that pregnenolone sulfate (PREGS) level is an important factor in differences in neurogenesis that are observed among the strains.
When we compared group I with group II, only one metabolite pregnenolone sulfate, decreasing in group I, was significantly different.
The clinical features of such a severe CAH subtype are the consequence of the enzymatic block at the level of the pregnenolone's and progesterone's conversion towards glucocorticoid and sex steroid production [5].
These tentatively identified metabolites containing various lysophosphatidylcholines and phosphatidylcholines, butyryl-L-carnitine, L-histidine, and putative pregnenolone sulfate (Table 1).
The first step in the path of P4 biosynthesis is performed by the cytochrome P450 side-chain cleavage (P450scc), which converts cholesterol into pregnenolone. In turn, pregnenolone is converted into the active metabolite, P4, by the action of the oxidoreductase enzyme 3[beta]-hydroxysteroid dehydrogenase/ [[DELTA].sup.5]-[[DELTA].sup.4] isomerase (3[beta]-HSD) [8].
Furthermore, the imaging findings upon presentation likely represent a result of chronic adrenal stimulation and steroid precursor buildup of cholesterol, pregnenolone, 17-OH pregnenolone, and dehydroepiandrosterone (Figure 3).
Kortner and Arukwe, (2007) reported the roles of steroidogenic acute regulatory protein (StAR) in the movement of cholesterol across the mitochondrial membrane and the final conversion to pregnenolone by cytochrome P450-mediated side-chain cleavage enzyme (P450scc), as a strong rate-limiting step in acute steroid production.