Abstract:
:In this study, we assessed the rate of estradiol degradation via the 17 beta-hydroxysteroid dehydrogenase (HSD) enzyme in breast tumors from postmenopausal women. We initially studied the effects of time, level of enzyme activity, amount of tissue assayed, and substrate concentration on the linearity of conversion of estradiol to estrone in breast tumor homogenates. The reaction was demonstrated to be linear when less than 15% conversion of estradiol to estrone occurred over 30 min with homogenates produced from 2.5 mg of tissue. Detailed kinetic experiments demonstrated the presence of two classes of enzyme activity, one with high affinity and the other with low affinity. In 83% of the tumors examined, the high affinity form was present and had a median Km of 0.62 microM and Vmax of 82 nmol/g protein/h. In 29 tumors, HSD activity could be precisely quantified and correlated with clinical parameters. No statistically significant correlation of enzyme activity with estrogen receptor (r2 = 0.06) or progesterone receptor (r2 = 0.006) or with patient age could be detected (r2 = 0.001). In 12 additional tumors, activity exceeded 15% conversion of estradiol to estrone at 30 min and precise quantitation was not possible. The average content of progesterone receptor was similar for these 12 tumors as for the 19 with lower HSD activity. However, estrogen receptor content and patient age were lower in the group with high HSD activity. The finding of a high affinity form of HSD in this study provides support for the biological importance of this enzyme in breast cancer tissues.
journal_name
Steroidsjournal_title
Steroidsauthors
Leszczynski D,Santner SJ,Feil PD,Santen RJdoi
10.1016/0039-128x(88)90020-7subject
Has Abstractpub_date
1988-03-01 00:00:00pages
299-316issue
3-4eissn
0039-128Xissn
1878-5867pii
0039-128X(88)90020-7journal_volume
51pub_type
杂志文章相关文献
STEROIDS文献大全abstract::Ethynylestradiol (EE2) is one of the most potent endocrine disrupting compounds capable to induce estrogenic effects even at trace level concentrations in the aquatic environment. Methods for detecting EE2 in such concentrations are generally based on GC or HPLC coupled to at least one mass spectrometer. Another appro...
journal_title:Steroids
pub_type: 杂志文章
doi:10.1016/j.steroids.2004.01.003
更新日期:2004-04-01 00:00:00
abstract::Seventeen cholesteryl alkyl ethers were synthesized through alcoholysis of cholesterol p-toluenesulfonate. This method was found superior to the etherification of sodium or potassium cholesterylate with alkyl halides or methanesulfonates, especially for the preparation of long-chain unsaturated aklyl ethers of [7(m)-3...
journal_title:Steroids
pub_type: 杂志文章
doi:10.1016/0039-128x(80)90109-9
更新日期:1980-01-01 00:00:00
abstract::A radioimmunoassay (RIA) method is described for the determination of 4-androstene-3, 11, 17-trione (11-oxo-androstenedione) in human plasma. 4-androstene-3, 11, 17-trione 3-(0-carboxymethyl) oxime-bovine serum albumin conjugate was used to generate highly specific antiserum in rabbits. Cross reactivities of several o...
journal_title:Steroids
pub_type: 杂志文章
doi:10.1016/s0039-128x(84)80013-6
更新日期:1984-07-01 00:00:00
abstract::The synthesis of seco-D and D-homo digitalis derivatives, from the carda-14,20(22)-dienolide 1, is described. Selective ozonolysis gave the seco-D 14-ketoaldehyde 2a. Modification of the two carbonyl groups and of the alpha, beta-unsaturated lactone ring of the seco-D 14-ketoaldehyde 2a allowed preparation of derivati...
journal_title:Steroids
pub_type: 杂志文章
doi:10.1016/s0039-128x(96)00117-1
更新日期:1996-10-01 00:00:00
abstract::In the present study, synthesis and antineoplastic activity of phenylacetic acid and benzoic acid nitrogen mustard conjugates of various steroidal oximes are reported for the first time. The conjugation was achieved through a more stable oxime-ester linkage and the resulting newly synthesized conjugates were evaluated...
journal_title:Steroids
pub_type: 杂志文章
doi:10.1016/j.steroids.2017.04.005
更新日期:2017-07-01 00:00:00
abstract::The aim of the present work was to analyze the effect of dehydroepiandrosterone (DHEA) on several metabolic risk factors, including cardiovascular health and insulin resistance, in aged rats submitted to a high-fat diet. For that, weaned rats were fed on a high-fat diet until 20 months of age. In the last 13 weeks of ...
journal_title:Steroids
pub_type: 杂志文章
doi:10.1016/j.steroids.2008.04.011
更新日期:2008-10-01 00:00:00
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...
journal_title:Steroids
pub_type: 杂志文章,评审
doi:10.1016/j.steroids.2007.07.009
更新日期:2007-11-01 00:00:00
abstract::The uterine milk (UTM) proteins are the major progesterone-regulated proteins secreted by the sheep uterus during pregnancy. Recently, proteins related to the UTM proteins have been identified in uterine secretions of the pregnant cow and sow. The present objective was to determine the time course for induction of the...
journal_title:Steroids
pub_type: 杂志文章
doi:10.1016/0039-128x(91)90022-n
更新日期:1991-12-01 00:00:00
abstract::The mechanistic aspects of the alkali-catalyzed rearrangement of 16alpha-hydroxy-17-keto steroid 1 to 17beta-hydroxy-16-keto steroid 2 are elucidated by use of (18)O- and deuterium-labeling experiments. The (18)O-labeling experiments refute the gem-hydration-quasi-diaxial dehydration mechanism for the rearrangement pr...
journal_title:Steroids
pub_type: 杂志文章
doi:10.1016/j.steroids.2008.03.001
更新日期:2008-09-01 00:00:00
abstract::Inhaled corticosteroids (ICS) are the standard of care in asthma and are widely used in the treatment of patients with COPD. The influence of steroids on inflammatory processes has long been established since glucocorticoids and their receptor belong to the regulatory network involved in inhibition of several inflamma...
journal_title:Steroids
pub_type: 杂志文章,评审
doi:10.1016/j.steroids.2006.10.007
更新日期:2007-01-01 00:00:00
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. ...
journal_title:Steroids
pub_type: 杂志文章
doi:10.1016/j.steroids.2012.12.007
更新日期:2013-03-01 00:00:00
abstract::The syntheses and antimitotic activity of several novel 18a-homo-analogs of 2-methoxyestradiol are described. Structural modifications of the parent 2-methoxy-18a-homoestradiol include introduction of unsaturation in the D-ring and methylation of the 17-OH. Of seven analogs synthesized, one has demonstrated superior b...
journal_title:Steroids
pub_type: 杂志文章
doi:10.1016/j.steroids.2007.11.003
更新日期:2008-02-01 00:00:00
abstract::A number of testosterone analogs with a 13,14-secosteroidal fragment have been prepared from (13S)-13-iodo-6beta-methoxy-3alpha, 5-cyclo-13,14-seco-5alpha-androstan-14,17-dione. The key steps involved stereoselective deiodination of the starting compound with triphenylphosphine and selective protection of the 17-keto ...
journal_title:Steroids
pub_type: 杂志文章
doi:10.1016/j.steroids.2004.04.010
更新日期:2004-07-01 00:00:00
abstract::Carbon-13 nuclear magnetic resonance spectra for 31 3 beta-hydroxy and acetoxy androstane derivatives bearing vicinal oxygenated functions at ring D with and without oxygenated functions at C-6 are reported. Relative substituent effects are discussed. ...
journal_title:Steroids
pub_type: 杂志文章
doi:10.1016/0039-128x(91)90077-9
更新日期:1991-04-01 00:00:00
abstract::During our studies of the hepatic androgen receptor in cynomolgus monkeys, tritiated mibolerone +/- a 200-fold excess of unlabeled mibolerone has been used to determine specific binding in cytosol. During time-course studies, high-capacity, unsaturable binding of [3H]mibolerone was noted after short-term incubations (...
journal_title:Steroids
pub_type: 杂志文章
doi:10.1016/0039-128x(95)00116-8
更新日期:1995-11-01 00:00:00
abstract::Steroid derivatives V, VI, VII and VIII reacted with Lawesson's reagent (LR) to produce spiro-oxazaphosphole-4',17-androstene derivative XI, diazaphospholoandrostane XIV and the thionated derivatives XVI and XVII, respectively. The structures of the new compounds were confirmed by analytical and spectroscopic evidence...
journal_title:Steroids
pub_type: 杂志文章
doi:10.1016/j.steroids.2004.11.001
更新日期:2005-03-01 00:00:00
abstract::A procedure utilizing co-chromatography and complementary antiserum comparisons was employed to assess the specificity of a cortisol radioimmunoassay for use in the chronically catheterized fetal sheep preparation. Complementary antiserum comparisons is a technique by which two different cortisol antisera, prepared fr...
journal_title:Steroids
pub_type: 杂志文章
doi:10.1016/s0039-128x(79)80005-7
更新日期:1979-01-01 00:00:00
abstract::Sex steroid-binding protein receptor was detected on membranes prepared from human premenopausal endometrium. The binding of sex steroid-binding protein to membranes was specific, saturable, and high affinity. Scatchard analysis showed the presence of two binding sites at different affinities. The addition of estradio...
journal_title:Steroids
pub_type: 杂志文章
doi:10.1016/0039-128x(91)90058-4
更新日期:1991-06-01 00:00:00
abstract::The syndrome of apparent mineralocorticoid excess (AME) is an inherited form of hypertension in which 11 beta-hydroxysteroid dehydrogenase (11-HSD) is defective. This enzyme converts cortisol to its inactive metabolite, cortisone. The deficiency allows mineralocorticoid receptors to be occupied by cortisol, because th...
journal_title:Steroids
pub_type: 杂志文章,评审
doi:10.1016/s0039-128x(96)00164-x
更新日期:1997-01-01 00:00:00
abstract::Oxidative stress is thought to play a crucial role in the pathogenesis of chronic diabetic complications. We investigated the protective effects of 17 beta-estradiol (E2) on alloxan-induced stress oxidant, hepatic dysfunction and histological changes in male rats liver and pancreas. Our results showed that 17 beta-est...
journal_title:Steroids
pub_type: 杂志文章
doi:10.1016/j.steroids.2007.12.026
更新日期:2008-05-01 00:00:00
abstract::Anabolic androgenic steroids (AAS) are testosterone and testosterone-derivative compounds sporadically employed by athletes and increasingly used recreationally to acquire a competitive edge or improve body composition. Nevertheless, users are subject to undesired side effects majorly associated with tissue-specific a...
journal_title:Steroids
pub_type: 杂志文章,评审
doi:10.1016/j.steroids.2020.108753
更新日期:2020-12-01 00:00:00
abstract::This study examined the role of protein kinase C enzymatic activity as a physiologic determinant of stromal cell death in decidua basalis (DB) during pregnancy. The expression of epidermal growth factor receptor (EGF-R) and Bcl2 was used as an indicator of stromal cell proliferation/survival, whereas Bax and the occur...
journal_title:Steroids
pub_type: 杂志文章
doi:10.1016/s0039-128x(99)00044-6
更新日期:1999-09-01 00:00:00
abstract::It is known that follicle-stimulating hormone (FSH) and insulin stimulate estradiol secretion from cultured non-luteinizing granulosa cells. The interaction between these hormones is less well understood. Granulosa cells from small (2-4 mm) bovine follicles were cultured in serum-free medium to determine if cytochrome...
journal_title:Steroids
pub_type: 杂志文章
doi:10.1016/s0039-128x(00)00218-x
更新日期:2001-06-01 00:00:00
abstract::MDL 18,962 was shown to be a highly specific, potent (Ki = 3-4 nM), enzyme-activated inhibitor of aromatase with minimal intrinsic endocrine properties. The affinity of MDL 18,962 was higher for human and baboon placental aromatase than for rhesus placental or rodent ovarian aromatase. These species differences necess...
journal_title:Steroids
pub_type: 杂志文章
doi:10.1016/0039-128x(83)90065-x
更新日期:1987-07-01 00:00:00
abstract::Periodontitis is a complication of diabetes mellitus, and the two diseases are highly associated with the dysfunction of inflammatory mediators. 25-hydroxyvitamin D(3) (25(OH)D(3)) plays a pivotal role in inflammatory modulation, but little is known about its effects on the progression of diabetic periodontitis and th...
journal_title:Steroids
pub_type: 杂志文章
doi:10.1016/j.steroids.2012.10.015
更新日期:2013-02-01 00:00:00
abstract::Steroidal nucleoside analogs were synthesized starting from testosterone. By reduction of the oxime of 17 beta-hydroxy-androst-4-en-3-one (testosterone), a mixture of the two amino epimers of C-3 were obtained. The 3 alpha-amino-androst-4-en-17 beta-ol was crystallized in 73% yield and coupled with 5-amino-4,6-dichlor...
journal_title:Steroids
pub_type: 杂志文章
doi:10.1016/s0039-128x(01)00157-x
更新日期:2002-03-01 00:00:00
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-...
journal_title:Steroids
pub_type: 杂志文章
doi:10.1016/0039-128x(75)90011-2
更新日期:1975-07-01 00:00:00
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...
journal_title:Steroids
pub_type: 杂志文章
doi:10.1016/j.steroids.2007.08.013
更新日期:2008-01-01 00:00:00
abstract::The efficiencies for estrogen conjugate hydrolysis were compared between enzyme hydrolysis, acid solvolysis and a new method, ammonolysis. Samples included: 1) crystalline 1,3,5(10)-estratriene-3, 17 beta-diol disulfate (estradiol 3,17-disulfate), 2) squirrel monkey urine collected following an intravenous injection o...
journal_title:Steroids
pub_type: 杂志文章
doi:10.1016/0039-128x(84)90023-0
更新日期:1984-06-01 00:00:00
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...
journal_title:Steroids
pub_type: 杂志文章
doi:10.1016/s0039-128x(98)00055-5
更新日期:1998-10-01 00:00:00