Browse
Submit Data
Databases
API
Help

Dataset Information

10 Views

0 Connections

0 Citations

0 Reanalyses

0 Downloads

Omics score: 0

Metabolism of 11-oxygenated steroids. Metabolism in vitro by preparations of liver.

ABSTRACT: 1. The isolation and partial purification of 11beta-hydroxy steroid dehydrogenase from rat and guinea-pig liver microsomes has been achieved by conventional methods. 2. The efficiency of different 11-oxygenated steroids as substrates has been examined. The relative efficiencies confirm in the main the stereochemical theory of the enzyme-coenzyme-substrate complex that was proposed earlier on the basis of studies in vivo. Delta(4)-3-Ketones and 5alpha-hydrogen steroids are readily metabolized by the enzyme. 5beta-Hydrogen steroids and Delta(4)-3-ketones with certain large alpha-substituents are metabolized to a limited extent or not at all. Halogen substitution in the 9alpha-position enhances the rate of reduction of 11-ketones but blocks the oxidation of the related 11beta-ols. 3. 9alpha-Fluorocortisol is a competitive inhibitor of the oxidation of cortisol, but 9alpha-fluorocortisone is reduced at five to ten times the initial velocity of cortisone. 4. 11beta-Hydroxy steroid dehydrogenase activity has been found in liver microsomes of rat, guinea pig, rabbit and calf. 5. Relative substrate efficiencies and K(m) values are similar in whole (debris-free) homogenates, washed microsomes and acetone-dried powders of washed microsomes. 6. A variety of conditions have been examined for the observation of 11beta-hydroxy steroid dehydrogenase activity. NADP(H) is an efficient and NAD(H) a very poor coenzyme for the reaction.

SUBMITTER: Bush IE

PROVIDER: S-EPMC1198650 | biostudies-other | 1968 Mar

REPOSITORIES: biostudies-other

ACCESS DATA

Json Xml

Similar Datasets

Adrenal-derived 11-oxygenated 19-carbon steroids are the dominant androgens in classic 21-hydroxylase deficiency.

Project description:To comprehensively characterize androgens and androgen precursors in classic 21-hydroxylase deficiency (21OHD) and to gain insights into the mechanisms of their formation.Serum samples were obtained from 38 patients (19 men) with classic 21OHD, aged 3-59, and 38 sex- and age-matched controls; 3 patients with 11?-hydroxylase deficiency; 4 patients with adrenal insufficiency; and 16 patients (8 men) undergoing adrenal vein sampling. Paraffin-embedded normal (n = 5) and 21OHD adrenal tissues (n = 3) were used for immunohistochemical studies.We measured 11 steroids in all sera by liquid chromatography-tandem mass spectrometry. Immunofluroescence localized 3?-hydroxysteroid dehydrogenase type 2 (HSD3B2) and cytochrome b5 (CYB5A) within the normal and 21OHD adrenals.Four 11-oxygenated 19-carbon (11oxC19) steroids were significantly higher in male and female 21OHD patients than in controls: 11?-hydroxyandrostenedione, 11-ketoandrostenedione 11?-hydroxytestosterone, and 11-ketotestosterone (3-4-fold, P < 0.0001). For 21OHD patients, testosterone and 11-ketotestosterone were positively correlated in females, but inversely correlated in males. All 11oxC19 steroids were higher in the adrenal vein than in the inferior vena cava samples from men and women and rose with cosyntropin stimulation. Only trace amounts of 11oxC19 steroids were found in the sera of patients with 11?-hydroxylase deficiency and adrenal insufficiency, confirming their adrenal origin. HSD3B2 and CYB5A immunoreactivities were sharply segregated in the normal adrenal glands, whereas areas of overlapping expression were identified in the 21OHD adrenals.All four 11oxC19 steroids are elevated in both men and women with classic 21OHD. Our data suggest that 11oxC19 steroids are specific biomarkers of adrenal-derived androgen excess.

| S-EPMC4874183 | biostudies-literature

Circulating 11-oxygenated androgens across species.

Project description:The androgen precursors, dehydroepiandrosterone (DHEA) and DHEA sulfate (DHEAS) are produced in high amounts by the adrenal cortex primarily in humans and a few other primates. The human adrenal also secretes 11-oxygenated androgens (11-oxyandrogens), including 11?-hydroxyandrostenedione (11OHA4), 11-ketoandrostenedione (11KA4), 11?-hydroxytestosterone (11OHT) and 11-ketotestosterone (11KT), of which 11OHT and 11KT are bioactive androgens. The 11-oxyandrogens, particularly 11KT, have been recognized as biologically important testicular androgens in teleost fishes for decades, but their physiological contribution in humans has only recently been established. Beyond fish and humans, however, the presence of 11-oxyandrogens in other species has not been investigated. This study provides a comprehensive analysis of a set of C19 steroids, including the traditional androgens and 11-oxyandrogens, across 18 animal species. As previously shown, serum DHEA and DHEAS were much higher in primates than all other species. Circulating 11-oxyandrogens, especially 11KT, were observed in notable amounts in male, but not in female trout, consistent with gonadal origin in fish. The circulating concentrations of 11-oxyandrogens ranged from 0.1 to 10?nM in pigs, guinea pigs and in all the primates studied (rhesus macaque, baboon, chimpanzee and human) but not in rats or mice, and 11OHA4 was consistently the most abundant. In contrast to fish, serum 11KT concentrations were similar in male and female primates for each species, despite significantly higher circulating testosterone in males, suggesting that 11KT production in these species is not testis-dependent and primarily originates from adrenal-derived 11-oxyandrogen precursors.

| S-EPMC6733521 | biostudies-literature

Clinical assessment of liver metabolism during hypothermic oxygenated machine perfusion using microdialysis.

Project description:BackgroundWhile growing evidence supports the use of hypothermic oxygenated machine perfusion (HOPE) in liver transplantation, its effects on liver metabolism are still incompletely understood.MethodsTo assess liver metabolism during HOPE using microdialysis (MD), we conducted an open-label, observational pilot study on 10 consecutive grafts treated with dual-HOPE (D-HOPE). Microdialysate and perfusate levels of glucose, lactate, pyruvate, glutamate, and flavin mononucleotide (FMN) were measured during back table preparation and D-HOPE and correlated to graft function and patient outcome.ResultsMedian (IQR) MD and D-HOPE time was 228 (210, 245) and 116 (103, 143) min. Three grafts developed early allograft dysfunction (EAD), with one requiring retransplantation. During D-HOPE, MD glucose and lactate levels increased (ANOVA = 9.88 [p = 0.01] and 3.71 [p = 0.08]). Their 2nd-hour levels were higher in EAD group and positively correlated with L-GrAFT score. 2nd-hour MD glucose and lactate were also positively correlated with cold ischemia time, macrovesicular steatosis, weight gain during D-HOPE, and perfusate FMN. These correlations were not apparent when perfusate levels were considered. In contrast, MD FMN levels invariably dropped steeply after D-HOPE start, whereas perfusate FMN was higher in dysfunctioning grafts.ConclusionMD glucose and lactate during D-HOPE are markers of hepatocellular injury and could represent additional elements of the viability assessment.

| S-EPMC9292750 | biostudies-literature

Metabolism of megestrol acetate and related progesterone analogues by liver preparations in vitro.

Project description:1. The rates of metabolism of megestrol acetate, 17alpha-acetoxy-6alpha-methylprogesterone, 6alpha-methylprogesterone, 17alpha-acetoxyprogesterone and progesterone by liver microsome-supernatant fractions from female rats and rabbits have been compared. 2. Introduction of the 6alpha-methyl group into the progesterone molecule markedly decreased the metabolism by liver microsome-supernatant preparations in the rat but not in the rabbit. When 17alpha-acetoxy was the substituting group, metabolism was diminished in the rabbit but not in the rat preparations. Introduction of both the 6alpha-methyl and 17alpha-acetoxy groups into the progesterone molecule markedly decreased the rate of metabolism by liver microsome-supernatant preparations of both species. The Delta(6)-bond in megestrol acetate confers additional resistance to metabolism by rabbit-liver preparations. 3. It is proposed that the observed inhibition of metabolism by these substituents in the progesterone molecule partly or wholly explains the enhanced activity of megestrol acetate.

| S-EPMC1264745 | biostudies-other

New 19-oxygenated steroids from the soft coral Nephthea chabrolii.

Project description:In order to search for novel bioactive substances from marine organisms, we investigated the acetone extract of the soft coral Nephthea chabrolii collected at San-Hsian-Tai, Taitong County, Taiwan. From this extract three new 19-oxygenated steroids, nebrosteroids N-P (1-3) were isolated. The structures of these compounds were elucidated by extensive spectroscopic analyses.

| S-EPMC3397439 | biostudies-literature

Abiraterone acetate treatment lowers 11-oxygenated androgens.

Project description:ContextThe human adrenal is the dominant source of androgens in castration-resistant prostate cancer (CRPC) and classic 21-hydroxylase deficiency (21OHD). Abiraterone, derived from the prodrug abiraterone acetate (AA), inhibits the activity of cytochrome P450 17-hydroxylase/17,20-lyase (CYP17A1), the enzyme required for all androgen biosynthesis. AA treatment effectively lowers testosterone and androstenedione in 21OHD and CRPC patients. The 11-oxygenated androgens are major adrenal-derived androgens, yet little is known regarding the effects of AA administration on 11-oxygenated androgens.ObjectiveTo test the hypothesis that AA therapy decreases 11-oxygenated androgens.DesignSamples were obtained from 21OHD or CRPC participants in AA or AA plus prednisone (AAP)-treatment studies, respectively.MethodsWe employed liquid chromatography-tandem mass spectrometry (LC-MS/MS) to measure the 11-oxygenated androgens, 11β-hydroxyandrostenedione, 11-ketoandrostenedione, 11β-hydroxytestosterone, and 11-ketotestosterone, in plasma or serum samples from six 21OHD and six CRPC patients before and after treatment with AA or AAP, respectively.ResultsIn CRPC patients, administration of AAP (1000 mg/day AA with prednisone and medical castration) lowered all four 11-oxygenated androgens to below the lower limits of quantitation (<0.1-0.3 nmol/L), equivalent to 64-94% reductions from baseline. In 21OHD patients, administration of AA (100-250 mg/day for 6 days) reduced all 11-oxygenated androgens by on average 56-77% from baseline.ConclusionsWe conclude that AA and AAP therapies markedly reduce the production of the adrenal-derived 11-oxygenated androgens, both in patients with high (21OHD) or normal (CRPC) 11-oxygenated androgens at baseline, respectively. Reduction of 11-oxygenated androgens is an important aspect of AA and AAP pharmacology.

| S-EPMC7096060 | biostudies-literature

Metabolism of a glutathione conjugate of 2-hydroxyoestradiol by rat liver and kidney preparations in vitro.

Project description:Adult male rat liver and kidney preparations were incubated with (2-hydroxyoestradiol-1-yl)[(35)S]glutathione. The glutamic acid and glycine residues were removed by enzymes present in the kidney microsomal fraction; the liver preparations had no effect. The resulting 2-hydroxyoestradiol-cysteine conjugate was acetylated at the alpha-amino group by both liver and kidney homogenates fortified with acetyl-coenzyme A, but not significantly in the absence of this coenzyme, or by liver or kidney slices. These results suggest that an oestrogen-glutathione conjugate, if formed in vivo, would be converted into the corresponding mercapturic acid before excretion.

| S-EPMC1185515 | biostudies-other

Production of 11-Oxygenated Androgens by Testicular Adrenal Rest Tumors.

Project description:ContextTesticular adrenal rest tumors (TART) are a common complication in males with classic 21-hydroxylase deficiency (21OHD). TART are likely to contribute to the androgen excess in 21OHD patients, but a direct quantification of steroidogenesis from these tumors has not been yet done.ObjectiveWe aimed to define the production of 11-oxygenated 19-carbon (11oxC19) steroids by TART.MethodsUsing liquid chromatography-tandem mass spectrometry, steroids were measured in left (n = 7) and right (n = 4) spermatic vein and simultaneously drawn peripheral blood (n = 7) samples from 7 men with 21OHD and TART. For comparison, we also measured the peripheral steroid concentrations in 5 adrenalectomized patients and 12 age- and BMI-matched controls. Additionally, steroids were quantified in TART cell- and adrenal cell-conditioned medium, with and without adrenocorticotropic hormone (ACTH) stimulation.ResultsCompared with peripheral blood from 21OHD patients with TART, the spermatic vein samples displayed the highest gradient for 11β-hydroxytestosterone (11OHT; 96-fold) of the 11oxC19 steroids, followed by 11-ketotestosterone (47-fold) and 11β-hydroxyandrostenedione (11OHA4; 29-fold), suggesting production of these steroids in TART. TART cells produced higher levels of testosterone and lower levels of A4 and 11OHA4 after ACTH stimulation compared with adrenal cells, indicating ACTH-induced production of testosterone in TART.ConclusionIn patients with 21OHD, TART produce 11oxC19 steroids, but in different proportions than the adrenals. The very high ratio of 11OHT in spermatic vs peripheral vein blood suggests the 11-hydroxylation of testosterone by TART, and the in vitro results indicate that this metabolism is ACTH-sensitive.

| S-EPMC8684463 | biostudies-literature

In Vitro Effects of Concomitant Use of Herbal Preparations on Cytochrome P450s Involved in Clozapine Metabolism.

Project description:Herbal supplements are increasingly used in psychiatric practice. Our epidemiological study has identified several herbal preparations associated with adverse outcomes of antipsychotic therapy. In this study, we evaluated the in vitro effects of four herbal preparations-Radix Rehmanniae (RR), Fructus Schisandrae (FS), Radix Bupleuri (RB) and Fructus Gardeniae (FG)-on cytochrome P450s (CYPs) involved in the metabolism of clozapine in human liver microsomes (HLMs) and recombinant human cytochrome P450 enzymes (rCYPs). N-desmethylclozapine and clozapine N-oxide, two major metabolites of clozapine, were measured using high-performance liquid chromatography (HPLC). FG, RR and RB showed negligible inhibitory effects in both in vitro systems, with estimated half-maximal inhibitory concentrations (IC50) and apparent inhibitory constant values (Ki) greater than 1 mg/mL (raw material), suggesting that minimal metabolic interaction occurs when these preparations are used concomitantly with clozapine. The FS extract affected CYP activity with varying potency; its effect on CYP 3A4-catalyzed clozapine oxidation was relatively strong (Ki: 0.11 mg/mL). Overall, the weak-to-moderate inhibitory effect of FS on in vitro clozapine metabolism indicated its potential role in herb-drug interaction in practice.

| S-EPMC6273925 | biostudies-literature

The partial characterization of 1-oxygenated steroids from urine of a hypertensive newborn child.

Project description:1. Four substances from the urine of a hypertensive newborn girl were partially characterized and shown to be 17alpha-hydroxy-5beta-pregnane-1,3,20-trione, 3alpha,17alpha-dihydroxy-5beta-pregnane-1,20-dione, 3alpha,17alpha,20alpha-trihydroxy-5beta-pregnan-1-one and 5beta-pregnane-1beta,3alpha,17alpha,20alpha-tetrol. 2. The characterization rested mainly on R(M) analysis of the substances and their derivatives by glycol fission, providing evidence for position and degree of substitution and for steroidal character. Supporting evidence was provided by chemically specific location reactions. 3. Certain problems in the manipulation of these beta-disubstituted steroids are discussed.

| S-EPMC1198792 | biostudies-other

OmicsDI is part of the ELIXIR infrastructure

OmicsDI is an Elixir interoperability service. Learn more ›

OmicsDI Databases

PRIDE
PeptideAtlas
MassIVE
JPOST Repository
Physiome Model Repository

EGA
EVA
ENA
LINCS
PAXDB
Cell Collective

MetaboLights
Metabolomics Workbench
MetabolomeExpress
GNPS
BioModels
FAIRDOMHub

ArrayExpress
dbGaP
ExpressionAtlas
GEO
NODE

Information

Databases
Help
API
Contact us
Code on GitHub
Terms of use
Submit Data