Without 17α-hydroxylase activity, pregnenolone and progesterone are not converted to 17-hydroxypregnenolone or 17-hydroxyprogesterone, impairing production of glucocorticoids. (medlineplus.gov)
Pregnenolone (PREG) and NADPH + H+ react to form 17alpha-hydroxypregnenolone (17aHPREG), NADP+, and H2O. (reactome.org)
Follow up with infants and young children about every 3-4 months for evaluation of height and weight, blood pressure, and laboratory monitoring (ie, pregnenolone, 17-hydroxypregnenolone, dehydroepiandrosterone [DHEA], plasma renin levels). (medscape.com)
Exogenous glucocorticoid therapy suppresses adrenocorticotropic hormone (ACTH) secretion and decreases pregnenolone, 17-hydroxypregnenolone, and DHEA levels. (medscape.com)
Dehydroepiandrosterone is a 17-Ketosteroid produced primarily by the adrenal gland by side chain cleavage of 17-Hydroxy Pregnenolone. (healthmatters.io)
Steroid 17 alpha hydroxylase/17,20 lyase (CYP17A1), associated with the endoplasmic reticulum membrane, catalyzes this reaction. (reactome.org)
Progesterone3
The enzyme has 17 alpha(α)-hydroxylase activity, converting pregnenalone to 17-hydroxypregnenolone and progesterone to 17-hydroxyprogesterone. (medlineplus.gov)
Alpha-Pregnanediol in men's urine is a significant metabolite of progesterone, and its levels can provide valuable insights into hormonal balance and potential health concerns related to progesterone and androgen metabolism. (healthmatters.io)
Alpha-Pregnanediol and Beta-Pregnanediol are metabolites of progesterone, and they are used as surrogate markers because they are the most abundant metabolites. (healthmatters.io)
Decreases1
For example, with styrene as the solute, the C coefRcient in the van Deemter equation decreases to a value that is only 17 of the C value when THF at 243C is the mobile phase (Figure 8). (forexinfolink.com)
Deficiency5
Dozens of mutations in the CYP17A1 gene have been found to cause 17α-hydroxylase/17,20-lyase deficiency. (medlineplus.gov)
Reduction of these activities leads to partial 17α-hydroxylase/17,20-lyase deficiency, while total loss of these activities leads to the more severe form of the disorder known as complete 17α-hydroxylase/17,20-lyase deficiency. (medlineplus.gov)
A small number of CYP17A1 gene mutations have been found to cause isolated 17,20-lyase deficiency, which is characterized by abnormal sexual development without hypertension or hypokalemia. (medlineplus.gov)
As in 17α-hydroxylase/17,20-lyase deficiency (described above), impairment of 17,20-lyase activity disrupts sex hormone production, leading to abnormal development of internal or external reproductive organs and delayed or absent puberty in affected individuals. (medlineplus.gov)
The genetic and functional basis of isolated 17,20-lyase deficiency. (medlineplus.gov)
CYP17A11
These mutations alter a region of the CYP17A1 protein that plays a role in the enzyme's 17,20-lyase function but not its 17α-hydroxylase function. (medlineplus.gov)
Activity4
Mutations associated with this condition reduce or eliminate both 17α-hydroxylase and 17,20-lyase activity. (medlineplus.gov)
A loss of 17,20-lyase activity impairs sex hormone production. (medlineplus.gov)
As a result, 17,20-lyase activity is severely reduced but 17α-hydroxylase activity is normal. (medlineplus.gov)
It is metabolized via the 5-alpha metabolic pathway (= increased 5α-reductase activity). (healthmatters.io)
Dehydroepiandrosterone6
17-hydroxyprogesterone (17-OHP), dehydroepiandrosterone (DHEA), and androstenedione (A) were measured after 2 h of insulin or saline infusion (zero time) and, subsequently, 30 and 60 min after an iv bolus of 0.25 mg ACTH-(1-24). (nih.gov)
Cytochrome P450 (P450, CYP) 17A1 plays a critical role in steroid metabolism, catalyzing both the 17α-hydroxylation of pregnenolone and progesterone and the subsequent 17α,20-lyase reactions to form dehydroepiandrosterone (DHEA) and androstenedione (Andro), respectively, critical for generating glucocorticoids and androgens. (nih.gov)
3-beta-hydroxysteroid dehydrogenase deficiency is indicated by an abnormal ratio of 17-hydroxypregnenolone to 17-hydroxyprogesterone and dehydroepiandrosterone to androstenedione . (medscape.com)
Androstenediol, derived from DEHYDROEPIANDROSTERONE by the reduction of the 17-keto group (17-HYDROXYSTEROID DEHYDROGENASES), is converted to TESTOSTERONE by the oxidation of the 3-beta hydroxyl group to a 3-keto group (3-HYDROXYSTEROID DEHYDROGENASES). (lookformedical.com)
More specifically, abiraterone inhibits the conversion of 17-hydroxypregnenolone to dehydroepiandrosterone (DHEA) by the enzyme CYP17A1 to decrease serum levels of testosterone and other androgens. (illnesshacker.com)
Impairment of 17,20-lyase activity2
This effect of insulin seems to be associated with a relative impairment of 17,20-lyase activity. (nih.gov)
As in 17α-hydroxylase/17,20-lyase deficiency (described above), impairment of 17,20-lyase activity disrupts sex hormone production, leading to abnormal development of internal or external reproductive organs and delayed or absent puberty in affected individuals. (medlineplus.gov)
3beta1
and no. 10, 3beta-methylcarbonate-androst-5-ene-7,17-dione] that have no androgenic activity and could also block the Adiol-induced AR transactivation in prostate cancer PC-3 cells. (lookformedical.com)
CYP17A1), a member of the cytochrome p450 family that catalyzes the 17alpha-hydroxylation of steroid intermediates involved in testosterone synthesis. (illnesshacker.com)
Lyase10
Here, we examined in detail the processivity of the 17α-hydroxylation and lyase steps. (nih.gov)
Dozens of mutations in the CYP17A1 gene have been found to cause 17α-hydroxylase/17,20-lyase deficiency. (medlineplus.gov)
Mutations associated with this condition reduce or eliminate both 17α-hydroxylase and 17,20-lyase activity. (medlineplus.gov)
Reduction of these activities leads to partial 17α-hydroxylase/17,20-lyase deficiency, while total loss of these activities leads to the more severe form of the disorder known as complete 17α-hydroxylase/17,20-lyase deficiency. (medlineplus.gov)
A loss of 17,20-lyase activity impairs sex hormone production. (medlineplus.gov)
A small number of CYP17A1 gene mutations have been found to cause isolated 17,20-lyase deficiency, which is characterized by abnormal sexual development without hypertension or hypokalemia. (medlineplus.gov)
These mutations alter a region of the CYP17A1 protein that plays a role in the enzyme's 17,20-lyase function but not its 17α-hydroxylase function. (medlineplus.gov)
As a result, 17,20-lyase activity is severely reduced but 17α-hydroxylase activity is normal. (medlineplus.gov)
The genetic and functional basis of isolated 17,20-lyase deficiency. (medlineplus.gov)
Abiraterone is an orally active inhibitor of the steroidal enzyme CYP17A1 (17 alpha-hydroxylase/C17,20 lyase). (illnesshacker.com)
Adrenal hyperplasia2
Both forms of adrenal hyperplasia are accompanied by elevated levels of 24-hour urinary 17-ketosteroids , the urinary metabolites of adrenal androgens. (medscape.com)
In contrast, hypertensive forms of adrenal hyperplasia (ie, 11-beta-hydroxylase deficiency and 17-alpha-hydroxylase deficiency) are associated with suppressed PRA and, often, hypokalemia. (medscape.com)
DHEA5
S)-Orteronel was three times more inhibitory toward the conversion of 17α-hydroxypregnenolone to DHEA than toward the 17α-hydroxylation of pregnenolone. (nih.gov)
IC50 values for (S)-orteronel were identical for blocking DHEA formation from pregnenolone and for 17α-hydroxylation, suggestive of processivity. (nih.gov)
Global kinetic modeling helped assign sets of rate constants for individual or groups of reactions, indicating that human P450 17A1 is an inherently distributive enzyme but that some processivity is present, i.e. some of the 17α-OH pregnenolone formed from pregnenolone did not dissociate from P450 17A1 before conversion to DHEA. (nih.gov)
Similarly, the 88% mortality rate seen in LPS challenge was reduced to 17% and 8.5%, by treatment with DHEA and AED, respectively. (lookformedical.com)
DHEA appears to mediate its protective effect by a mechanism that blocks the toxin-induced production of pathophysiological levels of tumour necrosis factor-alpha (TNF-alpha) and interleukin-1. (lookformedical.com)
Pregnenolone and progesterone1
Without 17α-hydroxylase activity, pregnenolone and progesterone are not converted to 17-hydroxypregnenolone or 17-hydroxyprogesterone, impairing production of glucocorticoids. (medlineplus.gov)
20202
O CCMAR organiza a 6 de Novembro de 2020, a XVII edição do Congresso da Sociedade Portuguesa de Etologia (SPE) que vai realizar-se, pela primeira vez, online. (ualg.pt)
Recent data suggest that insulin is a modulator of ovarian and adrenal steroidogenesis and that, in the ovary of hyperandrogenic women, hyperinsulinemia might cause dysregulation of cytochrome P450c17 alpha activity. (nih.gov)
In addition, we recently found that the quail brain expresses cytochrome P450 7α and produces 7α-and 7β-hydroxypregnenolone, previously undescribed avian neurosteroids, from pregnenolone. (elsevierpure.com)
Significantly1
The screening rate of anti-HCV antibody at 21-Hydroxypregnenolone prescreening and post-screening was significantly different ( 0.001) (Number 2). (immune-source.com)
Conversion1
High levels of 17-hydroxypregnenolone (Δ517OHP) are characteristic, but extra-adrenal conversion to 17-hydroxyprogesterone (17OHP) may lead to positive results on newborn screening tests. (nih.gov)
Concentrations1
MAYO ID: 23BPR Patients taking aspirin or nonsteroidal anti-inflammatory drugs (NSAID) may have decreased concentrations of prostaglandin F2 alpha. (pathologyservices.com)
Current1
We developed a liquid chromatography tandem mass spectrometry (LCMSMS) method to measure 17-hydroxyprogesterone in bloodspots to replace our current second-tier immunoassay method. (mdpi.com)
Vivo1
however, the AED effect was independent of TNF-alpha suppression, both in vivo and in vitro. (lookformedical.com)
Individuals2
The percentage of individuals with detectable HCV RNA among anti-HCV seropositive individuals decreased from 69.1% in the baseline 21-Hydroxypregnenolone group to 46.8% in the screening group ( 0.001). (immune-source.com)
The baseline group was defined as individuals who had laboratory tests before screening, and the screening group was defined as individuals who completed checks during the screening 21-Hydroxypregnenolone period. (immune-source.com)