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7-oxo-DHEA

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https://www.readbyqxmd.com/read/27369457/biohydroxylation-of-7-oxo-dhea-a-natural-metabolite-of-dhea-resulting-in-formation-of-new-metabolites-of-potential-pharmaceutical-interest
#1
Alina Świzdor, Anna Panek, Natalia Milecka-Tronina
Metabolism of steroids in healthy and unhealthy human organs is the subject of extensive clinical and biomedical studies. For this kind of investigations, it is essential that the reference samples of derivatives of new derivatives of natural, physiologically active steroids (especially those difficult to achieve in the chemical synthesis) become available. This paper demonstrated for the first time transformation of 7-oxo-DHEA - a natural metabolite of DHEA, by using Syncephalastrum racemosum cells. The single-pulse fermentation of substrate produced two new hydroxy metabolites: 1β,3β-dihydroxy-androst-5-en-7,17-dione, and 3β,12β-dihydroxy-androst-5-en-7,17-dione, along with the earlier reported 3β,9α-dihydroxy-androst-5-en-7,17-dione and 3β,17β-dihydroxy-androst-5-en-7-one...
July 2, 2016: Chemical Biology & Drug Design
https://www.readbyqxmd.com/read/27192427/synthesis-of-3%C3%AE-deuterated-7%C3%AE-hydroxy-dhea-and-7-oxo-dhea-and-application-in-lc-ms-ms-plasma-analysis
#2
Lucie Kolatorova Sosvorova, Jan Sarek, Jana Vitku, Miroslav Kvasnica
7-Oxygenated metabolites of dehydroepiandrosterone (DHEA) are known for their neuroprotective and immunomodulatory properties. These neuroactive steroids are currently predominately analysed by mass spectrometry, for which the use of internal deuterated standards is necessary. The aim of this study was to synthesize the deuterated derivatives of 7α-hydroxy-DHEA and 7-oxo-DHEA and test them in liquid chromatography-tandem mass spectrometry (LC-MS/MS) in order to enhance the performance characteristics of this method...
August 2016: Steroids
https://www.readbyqxmd.com/read/26855361/a-validated-lc-ms-ms-method-for-the-sensitive-quantitation-of-serum-7alpha-hydroxy-7beta-hydroxy-and-7keto-dehydroepiandrosterone-using-a-novel-derivatization-reagent
#3
Yuyong Ke, Renaud Gonthier, Jean-Nicolas Simard, Fernand Labrie
7alpha hydroxy-, 7beta hydroxy- and 7keto-dehydroepiandrosterone (7α OH-DHEA, 7β OH-DHEA and 7 oxo-DHEA) are oxidized metabolites of dehydroepiandrosterone (DHEA). Their concentrations are low in the circulation, especially in postmenopausal women, thus resulting in a considerable challenge for their reliable measurement. A sensitive and accurate LC-MS/MS method has been developed using a simple sample preparation procedure and a novel derivatization with 1-amino-4-methyl piperazine (MP). The derivatized metabolites are stable in high water content reagents...
April 2016: Steroids
https://www.readbyqxmd.com/read/26680484/steroid-hormones-and-homocysteine-in-the-outcome-of-patients-with-normal-pressure-hydrocephalus
#4
L Sosvorova, M Mohapl, M Hill, L Starka, M Bicikova, J Vitku, R Kanceva, J Bestak, R Hampl
Normal pressure hydrocephalus (NPH) is one of a few treatable conditions of cognitive decline affecting predominately elderly people. Treatment, commonly based on the ventriculoperitoneal shunt insertion, leads to a partial or complete correction of patient's state, although its effect does not unfortunately always last. The aim of our study was to observe the changes of homocysteine and selected steroids and neurosteroids and follow-up the patients with respect to the duration of the NPH-related dementia improvement...
2015: Physiological Research
https://www.readbyqxmd.com/read/26680473/steroid-hormones-related-to-11beta-hydroxysteroid-dehydrogenase-type-1-in-treated-obesity
#5
L Máčová, L Sosvorová, J Vítků, M Bičíková, M Hill, H Zamrazilová, B Sedláčková, L Stárka
The local concentration of glucocorticoids is intensively regulated by 11beta-hydroxysteroid dehydrogenase type 1 (11beta-HSD 1). Human 11beta-HSD 1 also reversibly catalyzes the inter-conversion of 7alpha-hydroxy- and 7beta-hydroxy-dehydroepiandrosterone (DHEA) into 7-oxo-DHEA. The cohort of 282 obese adolescents, 154 girls (median age 15.31 years, range 14.17-16.68 years) and 128 boys (median age 14.95 years, range 13.87-16.16 years), BMI (Body Mass Index) >90th percentile was examined. In samples collected before and after one month of reductive diet therapy, circulating levels of steroids were analyzed by liquid chromatography-tandem mass spectrometry and radioimmunoassay methods...
2015: Physiological Research
https://www.readbyqxmd.com/read/26134425/dehydroepiandrosterone-and-7-oxo-dehydroepiandrosterone-in-male-reproductive-health-implications-of-differential-regulation-of-human-sertoli-cells-metabolic-profile
#6
Tânia R Dias, Marco G Alves, Susana P Almeida, Joaquina Silva, Alberto Barros, Mário Sousa, Branca M Silva, Samuel M Silvestre, Pedro F Oliveira
Dehydroepiandrosterone (DHEA) is a precursor of androgen synthesis whose action is partially exerted through its metabolites. 7-Oxo-dehydroepiandrosterone (7-oxo-DHEA) is a common DHEA metabolite, non-convertible to androgens, which constitutes a promising therapeutic strategy for multiple conditions. Sertoli cells (SCs) are responsible for the support of spermatogenesis, having unique metabolic characteristics strongly modulated by androgens. Consequently, disruptions in androgen synthesis compromise SCs function and hence male fertility...
November 2015: Journal of Steroid Biochemistry and Molecular Biology
https://www.readbyqxmd.com/read/25976421/steroid-hormones-in-prediction-of-normal-pressure-hydrocephalus
#7
Lucie Sosvorova, Martin Hill, Milan Mohapl, Jana Vitku, Richard Hampl
Normal pressure hydrocephalus (NPH) is a treatable neurological disorder affecting elderly people with the prevalence increasing with age. NPH is caused by abnormal cerebrospinal fluid (CSF) reabsorption and manifested as a balance impairment, urinary incontinence and dementia development. These symptoms are potentially reversible if recognized early. Diagnosis of NPH is difficult and can be easily mistaken for other neurodegenerative disorders, which makes NPH one of the major misdiagnosed diseases worldwide...
August 2015: Journal of Steroid Biochemistry and Molecular Biology
https://www.readbyqxmd.com/read/25676787/determination-of-seven-selected-neuro-and-immunomodulatory-steroids-in-human-cerebrospinal-fluid-and-plasma-using-lc-ms-ms
#8
Lucie Sosvorova, Jana Vitku, Tereza Chlupacova, Milan Mohapl, Richard Hampl
Dehydroepiandrosterone (DHEA) and its 7-oxo- and 7-hydroxy-metabolites occurring in the brain are considered neurosteroids. Metabolism of the latter is catalysed by 11β-hydroxysteroid dehydrogenase (11β-HSD) which also interconverts cortisol and cortisone. The concurrent metabolic reaction to DHEA 7-hydroxylation is the formation of 16α-hydroxy-DHEA. The LC-MS/MS method using triple stage quadrupole-mass spectrometer was developed for simultaneous quantification of free DHEA, 7α-hydroxy-DHEA, 7β-hydroxy-DHEA, 7-oxo-DHEA, 16α-hydroxy-DHEA, cortisol and cortisone in human plasma and cerebrospinal fluid (CSF)...
June 2015: Steroids
https://www.readbyqxmd.com/read/24182335/reduced-levels-of-circulating-7alpha-hydroxy-dehydroepiandrosterone-in-treated-adolescent-obese-patients
#9
L Máčová, M Bičíková, H Zamrazilová, M Hill, H Kazihnitková, B Sedláčková, L Stárka
Elevated levels of glucocorticoids lead to the development of obesity and metabolic syndrome. Local glucocorticoid levels are regulated through the enzyme 11beta-hydroxysteroid dehydrogenase 1 (11beta-HSD 1), an enzyme that regenerates active cortisol from inert cortisone. Increased expression of 11beta-HSD 1 in adipose tissue promotes higher body mass index (BMI), insulin resistance, hypertension, and dyslipidemia. Human 11beta-HSD 1 is also responsible for inter-conversion of 7-hydroxylate metabolites of dehydroepiandrosterone (7-OH-DHEA) to their 7-oxo-form...
2014: Physiological Research
https://www.readbyqxmd.com/read/23123738/dhea-metabolites-activate-estrogen-receptors-alpha-and-beta
#10
Kristy K Michael Miller, Numan Al-Rayyan, Margarita M Ivanova, Kathleen A Mattingly, Sharon L Ripp, Carolyn M Klinge, Russell A Prough
Dehydroepiandrosterone (DHEA) levels were reported to associate with increased breast cancer risk in postmenopausal women, but some carcinogen-induced rat mammary tumor studies question this claim. The purpose of this study was to determine how DHEA and its metabolites affect estrogen receptors α or β (ERα or ERβ)-regulated gene transcription and cell proliferation. In transiently transfected HEK-293 cells, androstenediol, DHEA, and DHEA-S activated ERα. In ERβ transfected HepG2 cells, androstenedione, DHEA, androstenediol, and 7-oxo DHEA stimulated reporter activity...
January 2013: Steroids
https://www.readbyqxmd.com/read/19167490/epimerase-activity-of-the-human-11beta-hydroxysteroid-dehydrogenase-type-1-on-7-hydroxylated-c19-steroids
#11
Olivier Hennebert, Matthieu Montes, Alain Favre-Reguillon, Henry Chermette, Clotilde Ferroud, Robert Morfin
Cytochrome P4507B1 7alpha-hydroxylates dehydroepiandrosterone (DHEA), epiandrosterone (EpiA) and 5alpha-androstane-3beta,17beta-diol (Adiol). 11beta-Hydroxysteroid dehydrogenase type 1 (11beta-HSD1) interconverts 7alpha- and 7beta-forms. Whether the interconversion proceeds through oxido-reductive steps or epimerase activity was investigated. Experiments using [(3)H]-labelled 7beta-hydroxy-DHEA, 7beta-hydroxy-EpiA and 7beta-hydroxy-Adiol showed the (3)H-label to accumulate in the 7-oxo-DHEA trap but not in 7-oxo-EpiA or 7-oxo-Adiol traps...
March 2009: Journal of Steroid Biochemistry and Molecular Biology
https://www.readbyqxmd.com/read/17624766/7alpha-and-7beta-hydroxy-epiandrosterone-as-substrates-and-inhibitors-for-the-human-11beta-hydroxysteroid-dehydrogenase-type-1
#12
Olivier Hennebert, Christine Pernelle, Clotilde Ferroud, Robert Morfin
The human 11beta-hydroxysteroid dehydrogenase type 1 (11beta-HSD1) catalyzes both the NADP(H)-dependent oxido-reduction of cortisol and cortisone and the inter-conversion of 7alpha- and 7beta-hydroxy-dehydroepiandrosterone (DHEA) through a 7-oxo-DHEA intermediate. As shown with human liver and intestine fractions, 7alpha-hydroxy-epiandrosterone (7alpha-hydroxy-EpiA) and 7beta-hydroxy-EpiA were readily inter-converted with no evidence for a 7-oxo-EpiA intermediate. Whether this inter-conversion resulted from action of the 11beta-HSD1 or from an unknown epimerase is unresolved...
June 2007: Journal of Steroid Biochemistry and Molecular Biology
https://www.readbyqxmd.com/read/17467270/dehydroepiandrosterone-7alpha-hydroxylation-in-human-tissues-possible-interference-with-type-1-11beta-hydroxysteroid-dehydrogenase-mediated-processes
#13
Olivier Hennebert, Sonia Chalbot, Severine Alran, Robert Morfin
Dehydroepiandrosterone (DHEA) is 7alpha-hydroxylated by the cytochome P450 7B1 (CYP7B1) in the human brain and liver. This produces 7alpha-hydroxy-DHEA that is a substrate for 11beta-hydroxysteroid dehydrogenase type 1 (11beta-HSD1) which exists in the same tissues and carries out the inter-conversion of 7alpha- and 7beta-hydroxy-DHEA through a 7-oxo-intermediary. Since the role of 11beta-HSD1 is to transform the inactive cortisone into active cortisol, its competitive inhibition by 7alpha-hydroxy-DHEA may support the paradigm of native anti-glucocorticoid arising from DHEA...
May 2007: Journal of Steroid Biochemistry and Molecular Biology
https://www.readbyqxmd.com/read/17298836/a-novel-radioimmunoassay-of-7-oxo-dhea-and-its-physiological-levels
#14
COMPARATIVE STUDY
H Kazihnitková, L Zamrazilová, M Hill, O Lapcík, V Pouzar, R Hampl
A novel radioimmunoassay (RIA) of unconjugated 7-oxo-dehydroepiandrosterone (7-oxo-DHEA) in human serum was developed for the first time. This steroid is an intermediate in the biosynthesis of immunomodulatory 7-hydroxylated DHEA metabolites, and has been shown to possess thermogenic properties. The method employs polyclonal rabbit antiserum to (19E)-3beta-hydroxy-7,17,19-trione-19-O-(carboxymethyloxime):BSA conjugate and a homologous radioiodinated derivative with tyrosine methyl ester. The cross reactivity of the antiserum with structurally closest 7-hydroxyepimers of DHEA was lower than 1...
April 2007: Steroids
https://www.readbyqxmd.com/read/17152345/dehydroepiandrosterone-metabolites-and-their-interactions-in-humans
#15
Sonia Chalbot, Robert Morfin
Dehydroepiandrosterone (DHEA) is 7alpha-hydroxylated by the cytochrome P4507B1 in the liver, skin and brain, which are targets for glucocorticoids. 7alpha-Hydroxy-DHEA produced anti-glucocorticoid effects in vivo but the interference between the glucocorticoid hormone binding with its receptor could not be determined. In the organs mentioned above, circulating inactive cortisone is reduced to active cortisol by 11beta-hydroxysteroid dehydrogenase type 1 (11beta-HSD1). 7alpha-Hydroxy-DHEA is also a substrate for this enzyme...
2006: Drug Metabolism and Drug Interactions
https://www.readbyqxmd.com/read/17078923/redox-reactions-of-dehydroepiandrosterone-and-its-metabolites-in-differentiating-3t3-l1-adipocytes-a-liquid-chromatographic-mass-spectrometric-study
#16
Ashok Marwah, F Enrique Gomez, Padma Marwah, James M Ntambi, Brian G Fox, Henry Lardy
Dehydroepiandrosterone is known to depress fatty acid formation in differentiating 3T3-L1 adipocytes. The metabolism of dehydroepiandrosterone and four of its natural metabolites in differentiating adipocytes was studied by liquid chromatography-mass spectrometry. Adipocytes rapidly converted dehydroepiandrosterone to androst-5-ene-3beta,17beta-diol. 7alpha-Hydroxy-DHEA was interconverted with 7-oxo-DHEA and 7beta-hydroxy-DHEA and the corresponding 17beta reduced products. Dehydroepiandrosterone and its derivatives were detected only in the culture medium suggesting that dehydroepiandrosterone is metabolized via enzymes located in close proximity to, or that are integral parts of the cell membrane...
December 1, 2006: Archives of Biochemistry and Biophysics
https://www.readbyqxmd.com/read/16713254/the-native-anti-glucocorticoid-paradigm
#17
REVIEW
Caroline Muller, Olivier Hennebert, Robert Morfin
Circulating 3beta-hydroxysteroids including dehydroepiandrosterone (DHEA) are 7alpha-hydroxylated by the cytochrome P450-7B1 in the liver, skin and brain, which are the target organs of glucocorticoids. Anti-glucocorticoid effects with 7alpha-hydroxy-DHEA were observed in vivo without an interference with glucocorticoid binding to its receptor. In the organs mentioned above, the circulating inactive cortisone was reduced into active cortisol by the 11beta-hydroxysteroid dehydrogenase type 1 (11beta-HSD1). We demonstrated that 7alpha-hydroxy-DHEA was also a substrate for this enzyme...
July 2006: Journal of Steroid Biochemistry and Molecular Biology
https://www.readbyqxmd.com/read/16603347/inter-conversion-of-7alpha-and-7beta-hydroxy-dehydroepiandrosterone-by-the-human-11beta-hydroxysteroid-dehydrogenase-type-1
#18
Caroline Muller, Denis Pompon, Philippe Urban, Robert Morfin
The dehydroepiandrosterone (DHEA) 7alpha-hydroxylation in humans takes place in the liver, skin, and brain. These organs are targets for the glucocorticoid hormones where 11beta-hydroxysteroid dehydrogenase type 1 (11beta-HSD1) activates cortisone through its reduction into cortisol. The putative interference of 7alpha-hydroxy-DHEA with the 11beta-HSD1-catalyzed reduction of cortisone into cortisol has been confirmed in preliminary works with human liver tissue preparations of the enzyme demonstrating the transformation of 7alpha-hydroxy-DHEA into 7-oxo-DHEA and 7beta-hydroxy-DHEA...
June 2006: Journal of Steroid Biochemistry and Molecular Biology
https://www.readbyqxmd.com/read/16524719/dehydroepiandrosterone-and-its-metabolites-differential-effects-on-androgen-receptor-trafficking-and-transcriptional-activity
#19
COMPARATIVE STUDY
Qianxing Mo, Shi-fang Lu, Neal G Simon
Dehydroepiandrosterone (DHEA) is a multi-functional steroid that has been implicated in a broad range of biological effects in humans and rodents. Recent studies demonstrated that DHEA acts genomically through the androgen receptor (AR) in addition to its well-known effects on cell surface receptors. However, the relative contribution of DHEA and its major metabolites, including DHEA-Sulfate (DHEA-S), 7alpha-OH-DHEA, 7beta-OH-DHEA, 7-oxo-DHEA, androstenedione (Adione), and androstenediol (Adiol), in the production of genomic effects remains controversial, in part because the metabolism of DHEA varies in different cells and tissues...
April 2006: Journal of Steroid Biochemistry and Molecular Biology
https://www.readbyqxmd.com/read/16137639/interactions-between-dehydroepiandrosterone-and-glucocorticoid-metabolism-in-pig-kidney-nuclear-and-microsomal-11beta-hydroxysteroid-dehydrogenases
#20
Boaz Robinzon, Russell A Prough
The 11beta-hydroxysteroid dehydrogenase type 1 (11betaHSD1) activates glucocorticoids (GC) by reversibly converting 11-keto-GC to 11-hydroxy-GC, while 11betaHSD2 and 11betaHSD3 only catalyzes the reverse reaction. Recently, rat and human 11betaHSDs were shown to interconvert 7alpha- and 7beta-hydroxy-dehydroepiandrosterone (7alpha- or 7beta-OH-DHEA) with 7-oxo-DHEA. We report that pig kidney microsomes (PKMc) and nuclei (PKN) oxidize 7alpha-OH-DHEA to 7-oxo-DHEA at higher rates with NAD+, than with NADP+. Corticosterone (CS), dehydrocoticosterone (DHC), 11alpha- and 11beta-hydroxyprogesterone, and carbenoxolone completely inhibited these reactions, while 7-oxo-DHEA only inhibited the NAD+-dependent reaction...
October 1, 2005: Archives of Biochemistry and Biophysics
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