In vitro influence of plasma steroid-binding proteins on androgen metabolism in human leukocytes.


:The purpose of this study was to investigate the influence of plasma steroid-binding proteins on androgen metabolism in intact leukocytes prepared from normal male and female blood samples. Leukocyte preparations were incubated for 24 h at 37 degrees C with either labeled or unlabeled testosterone (T), 5 alpha-dihydrotestosterone (5 alpha-DHT), and androstenedione (A). After extraction, the formed labeled metabolites were first identified by high performance liquid chromatography, then, using unlabeled substrates, metabolite concentrations were measured by specific radioimmunoassays. The conversion ratios of substrate to metabolite were calculated for each preparation using either labeled or unlabeled substrates. In the absence of steroid-binding proteins, the mean conversion ratios of T to A, A to T, T to 5 alpha-DHT, and 5 alpha-DHT to 3 alpha-androstanediol (3 alpha-D) were, in males and females, respectively, 5.6% and 6.1% (n = 11), 5.6% and 5.6% (n = 5), 2.8% and 2.2% (n = 11), 43.1% and 40.0% (n = 5), these sex differences being non-significant. The presence of increasing amounts of plasma, purified albumin or sex hormone binding-globulin (SHBG) in the incubation media reduced metabolite formation dose-dependently. However, a 1000-fold greater concentration of albumin than of SHBG was necessary for 50% inhibition of androgen metabolism by leukocytes, showing SHBG to have the main protective effect.(ABSTRACT TRUNCATED AT 250 WORDS)






Déchaud H,Goujon R,Claustrat F,Boucherat M,Pugeat M




Has Abstract


1995-02-01 00:00:00
















  • In vitro and in vivo studies demonstrating potent and selective estrogen inhibition with the nonsteroidal aromatase inhibitor CGS 16949A.

    abstract::CGS 16949A inhibited the conversion of [4-14C]androstenedione (A) to [4-14C]estrone by human placental microsomes in a competitive manner (Ki = 1.6 nM). Aminoglutethimide, also a competitive inhibitor, had a Ki = 0.7 microM in this assay system. The Km for the aromatization of A was 0.11 microM. Using ovarian microsom...


    pub_type: 杂志文章


    authors: Steele RE,Mellor LB,Sawyer WK,Wasvary JM,Browne LJ

    更新日期:1987-07-01 00:00:00

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    abstract::Estrogen is the key regulator of bone metabolism in both men and women. Menopause and the accompanying loss of ovarian estrogens are associated with declines in bone mineral density (BMD): 10-year cumulative loss was 9.1% at the femoral neck and 10.6%, lumbar spine. Estradiol concentrations also predict fractures. Tot...


    pub_type: 杂志文章,评审


    authors: Cauley JA

    更新日期:2015-07-01 00:00:00

  • Synthesis and biological evaluation of novel C6-cyclo secondary amine substituted purine steroid-nucleosides analogues.

    abstract::Novel C6-cyclo secondary amine substituted purine steroid-nucleoside analogues (2-9) were efficiently synthesized through displacement of the C6 chloro on the purine ring of series 1 with versatile cyclic secondary amines, including pyrrolidines, piperidine, morpholine, and piperazines. All the newly-synthesized compo...


    pub_type: 杂志文章


    authors: Huang LH,Li Y,Xu HD,Zheng YF,Liu HM

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    pub_type: 杂志文章


    authors: Li JR,Kim DN

    更新日期:1979-03-01 00:00:00

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    pub_type: 杂志文章


    authors: Gainer JL,Kelly R

    更新日期:1976-09-01 00:00:00

  • Immunochemical detection of 5 alpha-reductase in human serum.

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    pub_type: 杂志文章


    authors: Lombardo ME,Hudson PB

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  • 1H NMR determination of adulteration of anabolic steroids in seized drugs.

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    pub_type: 杂志文章


    authors: Ribeiro MVM,Boralle N,Felippe LG,Pezza HR,Pezza L

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    pub_type: 杂志文章


    authors: Kasuya Y,Shibasaki H,Furuta T

    更新日期:2000-02-01 00:00:00

  • Presence of 11 beta-hydroxysteroid dehydrogenase in human semen: evidence of correlation with semen characteristics.

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    pub_type: 杂志文章


    authors: Nacharaju VL,Muneyyirci-Delale O,Khan N

    更新日期:1997-03-01 00:00:00

  • Studies directed toward a mechanistic evaluation of aromatase inhibition by androst-5-ene-7,17-dione. Time-dependent inactivation by the 19-nor and 5 beta, 6 beta-epoxy derivatives.

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    pub_type: 杂志文章


    authors: Numazawa M,Tachibana M

    更新日期:1997-07-01 00:00:00

  • Taccasubosides A-D, four new steroidal glycosides from Tacca subflabellata.

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    pub_type: 杂志文章


    authors: Li L,Ni W,Li XR,Hua Y,Fang PL,Kong LM,Pan LL,Li Y,Chen CX,Liu HY

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  • On reactions of steroidal 23-oxo and 23,24-epoxysapogenins with Lewis acids.

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    pub_type: 杂志文章


    authors: Jastrzebska I,Siergiejczyk L,Tomkiel AM,Urbańczyk-Lipkowska Z,Wójcik D,Morzycki JW

    更新日期:2009-08-01 00:00:00

  • Sterols of some Clerodendrum species (Verbenaceae): occurrence of the 24 alpha- and 24 beta-epimers of 24-ethylsterols lacking a delta 25-bond.

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    pub_type: 杂志文章


    authors: Akihisa T,Matsubara Y,Ghosh P,Thakur S,Tamura T,Matsumoto T

    更新日期:1989-03-01 00:00:00

  • New pregnane-type steroidal alkaloids from Sarcocca saligna and their cholinesterase inhibitory activity.

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    pub_type: 杂志文章


    authors: Atta-ur-Rahman,Feroz F,Naeem I,Zaheer-ul-Haq,Nawaz SA,Khan N,Khan MR,Choudhary MI

    更新日期:2004-10-01 00:00:00

  • 3β,5α,6β-Oxygenated sterols from the South China Sea gorgonian Muriceopsis flavida and their tumor cell growth inhibitory activity and apoptosis-inducing function.

    abstract::Three new polyhydroxysterols, named muriflasteroids A-C (1-3) were isolated from the South China Sea gorgonian Muriceopsis flavida, together with sixteen known analogs, cholest-3β,5α,6β-triol,3β-acetate (4), 5α-methoxycholest-3β,6β-diol (5), (22E)-cholest-22-en-3β,5α,6β-triol (6), cholest-3β,5α,6β-triol (7), (22E)-24-...


    pub_type: 杂志文章


    authors: Liu TF,Lu X,Tang H,Zhang MM,Wang P,Sun P,Liu ZY,Wang ZL,Li L,Rui YC,Li TJ,Zhang W

    更新日期:2013-01-01 00:00:00

  • Abiraterone and D4, 3-keto Abiraterone binding to CYP17A1, a structural comparison study by molecular dynamic simulation.

    abstract::The importance of computer-aided drug design and development is clear nowadays. These approaches smooth the way of designing some efficient candidates based on drugs in use. At this place, we studied the mechanism of D4-abiraterone (D4A), the active metabolite of Abiraterone (Abi), binding to CYP17A1 compared with Abi...


    pub_type: 杂志文章


    authors: Mehralitabar H,Ghasemi AS,Gholizadeh J

    更新日期:2021-01-17 00:00:00

  • Withanolides from the stems and leaves of Physalis pubescens and their cytotoxic activity.

    abstract::A phytochemical study of Physalis pubescens L. afforded twelve compounds, including six new withanolides (1, 4, and 6i-9), four new withanolide glucosides (2, 3, 5, and 6), and two known withanolides (10 and 11). Their structures were established via extensive spectroscopic analysis. The absolute configuration of 3 wa...


    pub_type: 杂志文章


    authors: Xia G,Li Y,Sun J,Wang L,Tang X,Lin B,Kang N,Huang J,Chen L,Qiu F

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  • Ethnic differences in the phenotypic expression of polycystic ovary syndrome.

    abstract::Polycystic ovary syndrome (PCOS) is the most common endocrine problem affecting women of reproductive age and is investigated from many regions of the world. Some reports have indicated ethnic difference in its manifestation. This review addressed the evidences for ethnic variation in the expression of PCOS phenotypes...


    pub_type: 杂志文章,评审


    authors: Zhao Y,Qiao J

    更新日期:2013-08-01 00:00:00

  • Contribution of exogenous progesterone to human adrenal cortisol synthesis in vitro: a comparison of early gestation fetal and adult tissues.

    abstract::The ability of human adult adrenal to utilize progesterone (P4) for cortisol (F) synthesis in vitro has been compared with that of fetal adrenal tissue. Explant cultures were studied for 6 days using Ham's F10 medium supplemented with 10% fetal bovine serum (FBS), with or without added P4 as substrate. Short-term (4h)...


    pub_type: 杂志文章


    authors: Branchaud CL,Lipowski L,Dhanani B,Goodyer CG,Lefebvre Y

    更新日期:1986-04-01 00:00:00

  • Synthesis of (20S)-[7,7,21,21-2H4]-3beta-(tert-butyldimethylsilanyloxy)-20-methyl-pregn-5-en-21-ol, a useful intermediate for the preparation of deuterated isotopomers of sterols.

    abstract::(20S)-[7,7,21,21-2H(4)]-3beta-(tert-Butyldimethylsilanyloxy)-20-methyl-pregn-5-en-21-ol, an intermediate for the preparation of deuterated isotopomers of sterols to be used as standards for biomedical studies, was prepared by reduction with dichloroaluminum deuteride of ethyl (20S)-3beta-(tert-butyldimethylsilanyloxy)...


    pub_type: 杂志文章


    authors: Ciuffreda P,Casati S,Bollini D,Santaniello E

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  • Determination of 11-deoxycortisol (Reichstein's compound S) in human plasma by clinical isotope dilution mass spectrometry using benchtop gas chromatography-mass selective detection.

    abstract::A first assay based on stable isotope dilution/gas chromatography-mass spectrometry (ID/GC-MS) has been developed for plasma 11-deoxycortisol (Reichstein's compound S), the leading hormonal marker of 11beta-hydroxylase deficiency. A suitable internal standard being unavailable, we synthesized dideuterated 11-deoxycort...


    pub_type: 杂志文章


    authors: Wudy SA,Hartmann M,Homoki J

    更新日期:2002-09-01 00:00:00

  • Synthesis and spectroscopic analysis of modified bile salts.

    abstract::For the study of hepatic bile acid transport in vivo, a series of modified bile salts were synthesized. The N-cholyl derivatives of L-leucine, L-alanine, D-alanine, beta-alanine, L-proline, and gamma-amino-butyric acid were prepared from cholic acid, ethyl chloroformate and the corresponding amino acid. Structural ana...


    pub_type: 杂志文章


    authors: Ballatore AM,Beckner CF,Caprioli RM,Hoffman NE,Liehr JG

    更新日期:1983-02-01 00:00:00

  • Synthesis of new steroid haptens for radioimmunoassay. Part III. 15beta-Carboxyethylmercaptosteroid-bovine serum albumin conjugates. Specific antisera for radioimmunoassay of 5alpha-dihydrotestosterone, 5alpha-androstane-3beta, 17beta-diol and 5alpha-andr

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    pub_type: 杂志文章


    authors: Rao PN,Khan AH,Moore PH Jr

    更新日期:1977-02-01 00:00:00

  • New synthetic strategy for the synthesis of 24-epibrassinolide.

    abstract::The synthesis of (22E,24R)-5 alpha-ergosta-2,22-dien-6-one (2), a key intermediate to the preparation of 24-epibrassinolide (1), was achieved through the 3,6-diketone 8 in a 40% overall yield in five steps starting from ergosterol (3). ...


    pub_type: 杂志文章


    authors: Brosa C,Puig R,Comas X,Fernández C

    更新日期:1996-09-01 00:00:00

  • Regulation of steroid production and its function within the corpus luteum.

    abstract::During the second half of the luteal phase, the human corpus luteum becomes responsive to regular luteinizing hormone (LH) pulses. These LH pulses stimulate progesterone secretion tonically, and during this tonic stimulation, additional LH-independent progesterone pulses occur, which are particularly pronounced in wom...


    pub_type: 杂志文章,评审


    authors: Wuttke W,Theiling K,Hinney B,Pitzel L

    更新日期:1998-05-01 00:00:00

  • Naturally occurring marine steroid 24-methylenecholestane-3β,5α,6β,19-tetraol functions as a novel neuroprotectant.

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    pub_type: 杂志文章


    authors: Leng T,Liu A,Wang Y,Chen X,Zhou S,Li Q,Zhu W,Zhou Y,Su X,Huang Y,Yin W,Qiu P,Hu H,Xiong ZG,Zhang J,Yan G

    更新日期:2016-01-01 00:00:00

  • A new sulphate metabolite as a long-term marker of metandienone misuse.

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    pub_type: 杂志文章


    authors: Gómez C,Pozo OJ,Garrostas L,Segura J,Ventura R

    更新日期:2013-12-11 00:00:00

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    pub_type: 杂志文章


    authors: Panarelli M,Holloway CD,Barr AB,Fraser R,Kenyon CJ

    更新日期:1995-01-01 00:00:00

  • New insights into the metabolism of tamoxifen and its role in the treatment and prevention of breast cancer.

    abstract::The metabolism of tamoxifen is being redefined in the light of several important pharmacological observations. Recent studies have identified 4-hydroxy N-desmethyltamoxifen (endoxifen) as an important metabolite of tamoxifen necessary for antitumor actions. The metabolite is formed through the enzymatic product of CYP...


    pub_type: 杂志文章,评审


    authors: Jordan VC

    更新日期:2007-11-01 00:00:00

  • In vivo metabolism of 3H-testosterone in adult male rats: effects of estrogen administration.

    abstract::The metabolism of testosterone (T) was studied in normal adult male rats using a constant infusion of trace amounts of the 3H-steroid into a tail vein for 3 h in order to attain a state of equilibrium. Samples of plasma, liver, kidney, prostate, seminal vesicles and muscle were analysed for 3H-testosterone, 3H-5alpha-...


    pub_type: 杂志文章


    authors: Lee DK,Bird CE,Clark AF

    更新日期:1975-07-01 00:00:00