Profiling of urinary formestane and confirmation by isotope ratio mass spectrometry.


:Formestane (F, androst-4-en-4-ol-3,17-dione) is an irreversible aromatase inhibitor with the ability to suppress the estrogen production from anabolic steroids. Consequently, F is mentioned on the World Anti-Doping Agency (WADA) prohibited list and because studies have shown that F is produced endogenously in small amounts, a threshold for urinary excreted F of 150 ng/mL was introduced. Lower concentrations could be due to endogenous production and need further investigation to prove the exact origin through determination of the carbon isotope ratio. However, because the current screening methods are a lot more sensitive, F is detected in practically every urine sample. A strict implementation of this WADA rule would imply that almost every urine sample needs additional investigation to verify an exogenous or endogenous origin. The main aim of this study was to propose and introduce a lower concentration limit of 25 ng/mL beneath which the detected F is considered as being endogenous and no further investigation is needed. The data presented in this paper suggests that this threshold provides a good balance between a sufficiently large detection window and not having to perform isotope ratio mass spectrometry (IRMS) analyses on negative urine samples.






Polet M,Van Renterghem P,Van Gansbeke W,Van Eenoo P




Has Abstract


2013-11-01 00:00:00
















  • 5 alpha-reductase inhibition by finasteride (Proscar) in epithelium and stroma of human benign prostatic hyperplasia.

    abstract::Finasteride is a specific 5 alpha-reductase inhibitor that has been shown to reduce the size of human benign prostatic hyperplasia (BPH) by inhibiting the intraprostatic conversion of testosterone to 5 alpha-dihydrotestosterone. The aim of the present in vitro study was to describe in more detail the inhibitory effect...


    pub_type: 杂志文章


    authors: Weisser H,Tunn S,Debus M,Krieg M

    更新日期:1994-11-01 00:00:00

  • The mechanism investigation in substitution of 21-bromo-3alpha-hydroxyl-3beta-methoxymethyl-5alpha-pregnan-20-one with nucleophiles.

    abstract::A mechanistic study on the nucleophilic substitution of a strictly geometric 21-bromo-3alpha-hydroxyl-3beta-methoxymethyl-5alpha-pregnan-20-one was described. Reaction of the alpha-bromoketone with excess lithium imidazole followed by the addition of extra bases including n-butyllithium, methyllithium, lithium piperid...


    pub_type: 杂志文章


    authors: Chen CY,Wong FF,Lee YH,Chou SY,Huang JJ,Yeh MY

    更新日期:2006-11-01 00:00:00

  • Cyclization of 13beta-ethyl-3-methoxy-17beta-ol-8,14-seco-1,3,5(10),9-gonatetraen-14-one and its 17 acetate derivative.

    abstract::13beta-Ethyl-3-methoxy-17beta-ol-8,14-seco-1,3,5(10),8-gonatetraen-14-one (IIIa) was isolated and its participation in the well-known acidic cyclization process was established. ...


    pub_type: 杂志文章


    authors: Makk N,Tóth G,Tömörkény E

    更新日期:1975-05-01 00:00:00

  • Endogenous steroid hormones in hair: Investigations on different hair types, pigmentation effects and correlation to nails.

    abstract::Steroid hormone analysis is widely used in health- and stress-related research to get insights into various diseases and the adaption to stress. Hair analysis has been used as a tool for the long-term monitoring of these steroid hormones. In this study, a liquid chromatography-tandem mass spectrometry (LC-MS/MS) metho...


    pub_type: 杂志文章


    authors: Voegel CD,Hofmann M,Kraemer T,Baumgartner MR,Binz TM

    更新日期:2020-02-01 00:00:00

  • Hormone mediated changes in monoamine stores and regulation of enzymes of biosynthesis and metabolism in the rat adrenal gland. Influence of progesterone, estradiol, ACTH and testosterone administration.

    abstract::The influence of daily injections, for 7 days, of 17-hydroxyprogesterone caproate (8 mg/100 g body weight pro die), of estradiol-17 beta 17-undecylate (1.2 mg/100 g body weight pro die) of testosterone enanthate (2 mg/100 g body weight pro die) and of ACTH (4 IU/100 g body weight pro die) to male Wistar rats, weighing...


    pub_type: 杂志文章


    authors: Bukhari AR,Guessab A,Nicol ML

    更新日期:1981-07-01 00:00:00

  • From ligand structure to biological activity: modified estratrienes and their estrogenic and antiestrogenic effects in MCF-7 cells.

    abstract::A variety of compounds, including the selective estrogen receptor (ER) modulators tamoxifen and raloxifene, phytoestrogens such as genistein, and xenoestrogens such as bisphenol, bind to the estrogen receptor and elicit biological responses. Structural studies have linked the altered activity of compounds such as 4-hy...


    pub_type: 杂志文章,评审


    authors: Brooks SC,Skafar DF

    更新日期:2004-06-01 00:00:00

  • Conjugates of steroids and anti-cancer agents. III. The synthesis of estrynamine and certain derivatives.

    abstract::Propargyl amine was protected by condensing it with 2,5-hexane-dione to give 2,5-dimethyl-N-(2'-propyn-1'-yl)pyrrole (2). The latter was converted to the corresponding Grignard reagent with ethylmagnesium bromide, and then condensed with estrone tetrahydropyranyl ether to give 17 alpha-[3'-(2'',5''-dimethyl-1''-pyrryl...


    pub_type: 杂志文章


    authors: Blickenstaff RT,Foster E,Gerzon K,Young P

    更新日期:1986-09-01 00:00:00

  • Dehydroepiandrosterone sulfate (DHEA-S) and DHEA-S-like compounds in fibrocystic disease of the breast.

    abstract::We assayed Type 1 (high K+) and Type 2 (high Na+) human breast cyst fluids for DHEA-S. When an antibody specific for the 3-sulfoconjugate end of DHEA-S was used, Type 1 cyst fluids (n = 18) showed a content of 114 +/- 68 micrograms/mL (mean +/- sigma) and Type 2 cyst fluids (n = 14) of 35 +/- 17 micrograms/mL (P less ...


    pub_type: 杂志文章


    authors: Chasalow FI,Blethen SL,Bradlow HL

    更新日期:1988-09-01 00:00:00

  • In vitro characterization of trimegestone: a new potent and selective progestin.

    abstract::Trimegestone (TMG) is a novel 19-norpregnane progestin under development for hormone replacement therapy and oral contraception. The objective of the current study was to characterize the potency and steroid receptor selectivity of TMG in several in vitro assays and to compare its activity to that of medroxyprogestero...


    pub_type: 杂志文章


    authors: Zhang Z,Lundeen SG,Zhu Y,Carver JM,Winneker RC

    更新日期:2000-10-01 00:00:00

  • Increased SULT1E1 activity in HepG2 hepatocytes decreases growth hormone stimulation of STAT5b phosphorylation.

    abstract::Mouse models of cystic fibrosis (CF) display increased sulfotransferase 1E1 (SULT1E1) activity in hepatocytes of cystic fibrosis transmembrane receptor (CFTR)-deficient animals. SULT1E1 is responsible for the sulfation and inactivation of beta-estradiol (E2) at physiological concentrations. IGF-1 message levels in CFT...


    pub_type: 杂志文章


    authors: Li L,He D,Wilborn TW,Falany JL,Falany CN

    更新日期:2009-01-01 00:00:00

  • Synthesis of C-2 and C-4 deuterium-labeled estradiol-17 beta.

    abstract::Estradiol-17 beta labeled with deuterium in the positions 2 or 4 can be prepared from 2-chloromercurio-1,3,5(10)-estratriene-3,17 beta-diol 3-methyl ether 17-acetate or 4-chloromercurio-1,3,5(10)-estratriene-3,17 beta-diol, respectively, in refluxing CH3COO(2)H/(2)H2O. The same reaction performed on 4-acetoxymercurio-...


    pub_type: 杂志文章


    authors: Ferraboschi P,Ravasi M,Santaniello E

    更新日期:1983-06-01 00:00:00

  • Distribution and metabolism of F6-1,25(OH)2 vitamin D3 and 1,25(OH)2 vitamin D3 in the bones of rats dosed with tritium-labeled compounds.

    abstract::26,26,26,27,27,27-Hexafluo-1,25(OH)2 vitamin D3, the hexafluorinated analog of 1,25(OH)2 vitamin D3, has been reported to be several times more potent than the parent compound regarding some vitamin D actions. The reason for enhanced biologic activity in the kidneys and small intestine appears to be related to F6-1,25...


    pub_type: 杂志文章


    authors: Komuro S,Kanamaru H,Nakatsuka I,Yoshitake A

    更新日期:1998-10-01 00:00:00

  • Adrenalectomy amplifies aldosterone induced injury in cardiovascular tissue: an effect attenuated by adrenally derived steroids.

    abstract::Aldosterone induces fibrotic changes in cardiovascular tissues but its effects have usually been demonstrated in models of pre-existing renal injury and/or hypertension. This study tests the hypothesis that aldosterone can directly induce vascular fibrotic changes in the absence of prior renal injury or hypertension. ...


    pub_type: 杂志文章


    authors: Brem AS,Morris DJ,Li X,Ge Y,Shaw S,Gong R

    更新日期:2013-03-01 00:00:00

  • Characterization of desoxymethyltestosterone main urinary metabolite produced from cultures of human fresh hepatocytes.

    abstract::Desoxymethyltestosterone (DMT; 17β-hydroxy-17α-methyl-5α-androst-2-ene) is a designer steroid present in hormonal supplements distributed illegally as such or in combination with other steroids, for self-administration. It figures on the list of substances prohibited in sports and its detection in athlete's urine samp...


    pub_type: 杂志文章


    authors: Gauthier J,Poirier D,Ayotte C

    更新日期:2012-05-01 00:00:00

  • The physiology functions of estrogen receptor α (ERα) in reproduction cycle of ovoviviparous black rockfish, Sebastes schlegeli Hilgendorf.

    abstract::This paper revealed the expression pattern of ERα in the ovoviviparous teleost, Sebastes schlegeli. In this paper, we isolated the cDNA encoding for estrogen receptor alpha of black rockfish (S. schlegeli) from its ovary, named as black rockfish ERα (brfERα). The cDNA sequence of brfERα consists of 2972bp with an open...


    pub_type: 杂志文章


    authors: Shi D,Wen HS,He F,Li JF,Yang YP,Chen CF,Zhang JR,Chen XY,Jin GX,Shi B,Qi BX,Li N

    更新日期:2011-12-20 00:00:00

  • Androgen receptor isoforms AR-A and AR-B display functional differences in cultured human bone cells and genital skin fibroblasts.

    abstract::Two isoforms of the androgen receptor (AR-A and AR-B), differing by a lack of the first 187 amino acids in the NH2-terminal transactivation domain of AR-A, are expressed in connective tissue and bone. Transient transfections of normal human osteoblastic cells (HOB) and of genital skin fibroblasts defective in AR (GSF-...


    pub_type: 杂志文章


    authors: Liegibel UM,Sommer U,Boercsoek I,Hilscher U,Bierhaus A,Schweikert HU,Nawroth P,Kasperk C

    更新日期:2003-12-01 00:00:00

  • Expeditious synthesis of steroids containing a 2-methylsulfanyl-acetyl side chain as potential glucocorticoid receptor imaging agents.

    abstract::In our effort to develop imaging agents for brain glucocorticoid receptors, we have prepared several novel glucocorticoids possessing a 2-methylsulfanyl-acetyl side chain. The synthesis was accomplished via a Mitsunobu reaction with thiobenzoic acid starting from cortisol, prednisolone, dexamethasone and triamcinolone...


    pub_type: 杂志文章


    authors: Wuest F,Carlson KE,Katzenellenbogen JA

    更新日期:2008-01-01 00:00:00

  • Progesterone receptors in endometrial cancer invasion and metastasis: development of a mouse model.

    abstract::Progestagens inhibit growth of endometrial cancer cells in vivo and in vitro, and also are reported to inhibit endometrial cancer cell invasion. The progesterone receptor (PR) isotypes PRA and PRB have different transcriptional activity. There are indications that relative over expression of PRB could lead to developm...


    pub_type: 杂志文章


    authors: Hanekamp EE,Gielen SC,van Oosterhoud SA,Burger CW,Grootegoed JA,Huikeshoven FJ,Blok LJ

    更新日期:2003-11-01 00:00:00

  • A convenient strategy for the annulation of aryl scaffold to A/B-ring steroids under microwave irradiation.

    abstract::A facile strategy for the annulation of 2,6-dicyanoaniline moiety to steroidal A/B-ring is described from base catalyzed and microwave-promoted reaction of steroidal 3-keto-2-hydroxymethylenes with malononitrile in high yields. The generality of the reaction has been extended to non-steroidal cyclic and aliphatic keto...


    pub_type: 杂志文章


    authors: Barthakur MG,Hasib A,Gogoi J,Boruah RC

    更新日期:2010-06-01 00:00:00

  • Heme availability affects corticosterone and aldosterone biosynthesis in rat adrenal.

    abstract::In this paper, we studied the effect of heme availability on corticosterone and aldosterone synthesis in rat adrenal. We found that hemin stimulated corticosterone and aldosterone production in adrenal homogenates in a dose-dependent fashion. Hemin administration to rats also provoked an increase in both corticosteron...


    pub_type: 杂志文章


    authors: Martini CN,Vaena de Avalos SG,Romero DG,San Martín de Viale L,Vila Mde C

    更新日期:1997-12-01 00:00:00

  • Kinetics of inhibition of estrogen 2-hydroxylase by various haloestrogens.

    abstract::Inhibitors of estrogen 2-hydroxylase can be utilized in studying the kinetics of this cytochrome P450 enzyme complex and in elucidating the structural requirements of the active site. The conversion of estrogens to 2-hydroxyestrogens in rat liver microsomal preparations was examined using two radiotracer assays, the c...


    pub_type: 杂志文章


    authors: Brueggemeier RW,Kimball JG

    更新日期:1983-07-01 00:00:00

  • Biotransformation and molecular docking studies of aromatase inhibitors.

    abstract::Bioconversion of the aromatase inhibitor formestane (4-hydroxyandrost-4-ene-3,17-dione) (1) by the fungus Rhizopus oryzae ATCC 11145 resulted in a new minor metabolite 3,5α-dihydroxyandrost-2-ene-4,17-dione (2) and the known 4β,5α-dihydroxyandrostane-4,17-dione (3) as the major product. The structural elucidation and ...


    pub_type: 杂志文章


    authors: Martin GD,Narvaez J,Bulmer R,Durrant MC

    更新日期:2016-09-01 00:00:00

  • Molecular mechanisms of testosterone action in spermatogenesis.

    abstract::Testosterone is required for the maturation of male germ cells, the production of sperm and thus male fertility. However, the mechanisms by which testosterone regulates spermatogenic processes have not been well defined. In this review, classical and non-classical pathways of testosterone signaling in the Sertoli cell...


    pub_type: 杂志文章,评审


    authors: Walker WH

    更新日期:2009-07-01 00:00:00

  • All progestins are not created equal.

    abstract::A variety of progestins are available for therapeutic use. It is convenient to classify them into those related in chemical structure to progesterone or testosterone. Progestins related to progesterone can be subdivided into pregnanes and 19-norpregnanes, whereas those related to testosterone can be subdivided into th...


    pub_type: 杂志文章,评审


    authors: Stanczyk FZ

    更新日期:2003-11-01 00:00:00

  • Synthesis and biological evaluation of novel sarsasapogenin derivatives as potential anti-tumor agents.

    abstract::Based on the fact that timosaponin A-III (TA-III) exhibits potent cytotoxic effects and has been considered as a potential anti-tumor agent, a range of novel sarsasapogenin derivatives 1, 2a-2g, 3, 4, 5, 6a-6g have been synthesized by a simple and facile synthetic route. The in vitro cytotoxic activity of these synthe...


    pub_type: 杂志文章


    authors: Yin Y,Zhao XC,Wang SJ,Gao PY,Li LZ,Ikejima T,Song SJ

    更新日期:2015-01-01 00:00:00

  • Progesterone and 17 alpha-OH-progesterone in concentrations similar to that of preovulatory follicular fluid is without effect on resumption of meiosis in mouse cumulus enclosed oocytes cultured in the presence of hypoxanthine.

    abstract::Some intermediates in the cholesterol biosynthesis between lanosterol and cholesterol are capable of inducing resumption of meiosis in cultured mouse oocytes without the presence of gonadotropins. The mechanism by which these so-called Meiosis Activating Sterols (MAS) activate the meiotic process is unknown, and it is...


    pub_type: 杂志文章


    authors: Yding Andersen C,Byskov AG

    更新日期:2002-11-01 00:00:00

  • A radioimmunoassay for 7 alpha-hydroxy dehydroepiandrosterone in human plasma.

    abstract::A radioimmunoassay for plasma 3 beta, 7 alpha-dihydroxy-5-androsten-17-one (7 alpha-hydroxy DHA) has been developed using anti-sera raised against 3 beta, 7 alpha-dihydroxy-5-androstene-17 beta-carboxyl-bovine serum albumin conjugate and [1, 2 (n) - 3H] 7 alpha-hydroxy DHA as the radioligand. Significant cross reactiv...


    pub_type: 杂志文章


    authors: Skinner SJ,Tobler CJ,Couch RA

    更新日期:1977-09-01 00:00:00

  • Ionotropin is the mammalian digoxin-like material (DLM). It is a phosphocholine ester of a steroid with 23 carbon atoms.

    abstract::We describe a novel steroid, which we have named "Ionotropin". Its unique features are: [1] it has 23 carbon atoms and [2] it is a phosphocholine ester. There are no other known mammalian steroids with either structural feature. Ionotropin cross reacts with digoxin-specific antibodies and may be the long-sought, endog...


    pub_type: 杂志文章


    authors: Chasalow F,Pierce-Cohen L

    更新日期:2018-08-01 00:00:00

  • Studies of the synthesis of biomarkers. VII. Synthesis of 5 alpha-(17R,20R)-14,15-secocholestane.

    abstract::5 alpha-(17R,20R)-14,15-Secocholestane (12) was synthesized from cholesterol (1) in 12 steps. The key intermediate, 5 alpha-cholest-14-en-3 beta-yl acetate (4), underwent ozonization, reduction, hydrolysis, and oxidation to provide 5 alpha-14,15-secocholesta-3,14,15-trione (8). One of the Clemmensen reduction products...


    pub_type: 杂志文章


    authors: Li TS,Li YL,Liang XT

    更新日期:1990-06-01 00:00:00

  • Structural classification of steroid-binding sites on proteins by coarse-grained atomic environment and its correlation with their biological function.

    abstract::Steroid hormone is extensively used for transmitting variety of biological signals in organisms. Natural steroid hormone is synthesized from cholesterol in adrenal cortex and in sexual gland in vertebrates. Appropriately dosed synthetic steroid hormones can be used for medication. Despite their positive effects as med...


    pub_type: 杂志文章


    authors: Hori-Tanaka Y,Yura K,Takai-Igarashi T,Tanaka H

    更新日期:2015-04-01 00:00:00