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Lázár G, Lázár G, Husztik E, Duda E, Agarwal MK. The influence of antiglucocorticoids on stress and shock. Ann N Y Acad Sci 1995; 761:276-95. [PMID: 7625726 DOI: 10.1111/j.1749-6632.1995.tb31384.x] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/26/2023]
Affiliation(s)
- G Lázár
- Institute of Pathophysiology, Albert Szent-Györgyi Medical University, Hungary
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Mirshahi M, Mirshahi A, Nato A, Agarwal MK. Receptor mediated mineralocorticoid action in alga cell mutants. FEBS Lett 1992; 314:237-40. [PMID: 1334844 DOI: 10.1016/0014-5793(92)81479-6] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/26/2022]
Abstract
The multiplication of Chlamydomonas cells can be arrested by the spirolactone derivative RU 26752 and this is fully reversible by the natural hormone aldosterone. Continuous growth in the presence of RU 26752 led to the isolation of a population subsequently resistant to the action of mineralocortoid analogues, due possibly to the selection of mutant cells. Immunophotochemical evidence is provided for a 52 kDa protein that possesses functional steroid and DNA binding domains. Alga cells therefore appear to respond to steroid hormones in a manner similar to the mammalian systems, possibly via a receptor that may represent a pygmy ancestor of the latter day steroid receptor superfamily.
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Affiliation(s)
- M Mirshahi
- INSERM U-86, Centre Universitaire des Cordeliers, Paris, France
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Mirshahi M, Pagano M, Razaghi A, Lazar G, Agarwal MK. Immunophotochemical analysis of mineralocortin by polyclonal antibodies against the native receptor from rat kidney. BIOCHEMICAL MEDICINE AND METABOLIC BIOLOGY 1992; 47:133-44. [PMID: 1325165 DOI: 10.1016/0885-4505(92)90017-s] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/26/2022]
Abstract
We have obtained a polyclonal antiserum by immunizing fawn Burgundy rabbits with the mineralocorticoid receptor (MCR) purified biochemically from rat kidneys. High titers of anti-MCR activity were obtained in radioimmunoassays within 3 weeks and increased with a booster shot. In Western blot analysis, the antibody revealed a major band of 94-98 kDa in renal cytosol from rat and beef kidneys. We also developed a fluorographic procedure where the MCR linked covalently to tritiated R-5020, following ultraviolet irradiation, gave imprints superimposable on the Western blot profile. The fluorographic pattern was specific since it was largely abolished in the presence of cold RU 26752 that is specific to MCR, or mineralocortin. The immune IgG precipitated rat renal MCR(-)[3H]RU 26752 complexes in a dose-dependent manner and also recognized MCR bound to the natural hormone aldosterone. During gel permeation chromatography on Sephacryl, the elution profile of [3H]RU 26752 shifted to high-molecular-weight regions in the presence of immune IgG. The receptor protein could be immunolocalized primarily to the principal cells of the collecting duct in rat kidney but the intercalated cells and glomeruli were not labeled, contrary to beef kidney where a uniform pattern of immunostaining was evident. These should permit large-scale purification of the MCR for detailed physicochemical studies and for screening of the MCR-positive tissues during various pathophysiological syndromes.
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Affiliation(s)
- M Mirshahi
- Department of Ophthalmology, Centre Universitaire des Cordeliers, Paris, France
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Lazar G, Pagano M, Agarwal MK. Purification and characterization of the activated mineralocorticoid receptor from rat myocardium. BIOCHIMICA ET BIOPHYSICA ACTA 1990; 1033:41-8. [PMID: 2154263 DOI: 10.1016/0304-4165(90)90192-y] [Citation(s) in RCA: 20] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/30/2022]
Abstract
Cardiac cytosol from adrenalectomized rats was radiolabelled with 10 nM tritiated RU 26752, R 5020 or aldosterone, to saturate the mineralocorticoid receptor (MCR) in the presence of 1 microM RU 38486 to block the glucocorticoid and progestin receptors. Free steroids were removed by charcoal treatment and the radiolabelled cytosol was passed through a phosphocellulose column. The MCR peak in the phosphocellulose eluate was activated at 25 degrees C for 45 min, adsorbed onto the DNA-cellulose and finally extracted once each with buffers containing 1 M potassium chloride or 25 mM magnesium chloride. The pooled DNA-cellulose extracts, reequilibrated with 10 nM [3H]RU 26752, were resolved as a single, homogeneous band of 78 kDa upon polyacrylamide gel electrophoresis. Ion-exchange analysis of the purified MCR on DEAE-cellulose-52 revealed a single peak in the 0.017 M sodium phosphate region with both RU 26752 and R 5020, but aldosterone dissociated during this procedure. Molecular filtration on Ultrogel AcA-44 columns revealed a major 145 kDa peak, with some smaller components of 40 and 80 kDa. These hydrodynamic properties of the purified MCR are at variance with those of the native receptor in crude myocardial cytosol, and suggest that some post-translational modifications in vivo may be required for the expression of MCR-mediated responses.
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Affiliation(s)
- G Lazar
- Institute of Pathophysiology, Szeged Medical School, Hungary
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Lazar G, Pagano M, Agarwal MK. Purification and characterization of the activated mineralocorticoid receptor from rat kidney. THE INTERNATIONAL JOURNAL OF BIOCHEMISTRY 1990; 22:621-30. [PMID: 2165926 DOI: 10.1016/0020-711x(90)90039-6] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/30/2022]
Abstract
1. The mineralcorticoid receptor (MR) from rat kidney was purified within 8 hr by the following, successive steps: stabilization with synthetic, tritiated steroids (RU 26752 or R 5020), phosphocellulose passage, heat activation (25 degrees C), and DNA-cellulose batch elution. 2. The purified preparation was resolved as a single, 75 KDa band on SDS-PAGE electrophoresis although the exact degree of purity was difficult to assess by the charcoal assay due to denaturation. 3. The natural hormone, aldosterone, was unsuitable for receptor purification and characterization. 4. The MR purified with different ligands behaved identically during ion exchange and gel permeation analyses, suggesting post-translational modifications of the native receptor in whole cytosol that exhibits molecular heterogeneity.
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Affiliation(s)
- G Lazar
- Department of Biochemistry, UFR Broussais, Centre Universitaire des Cordeliers, Paris, France
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Meyer WJ, Nichols NR, Nguyen HH. A physico-chemical comparison of aortic receptors in rat hypertension models. Life Sci 1986; 39:1231-6. [PMID: 3762307 DOI: 10.1016/0024-3205(86)90183-9] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/07/2023]
Abstract
Rat models of genetic hypertension include spontaneous hypertension and resistance or sensitivity to mineralocorticoid and salt induced hypertension. Previously, altered aldosterone binding to corticoid receptor I was found in aortic smooth muscle cells cultured from Fischer 344 rats which are extremely resistant to steroid and salt induced hypertension. The corticoid receptor I of Fisher 344 rats had a lower affinity than that of salt sensitive Wistar-Kyoto controls, as well as spontaneously hypertensive rats and Sprague-Dawley rats. In the present study, we have used DEAE-cellulose ion exchange chromatography to compare the structure (charge properties) and steroid specificity of vascular corticoid receptor I and II sites in these same rat hypertension models. No variations in ion exchange properties of type I and II receptors were found. Together with the lower aldosterone affinity of corticoid receptor I sites in Fischer 344 rats these data suggest an altered binding domain which is not seen as a difference in charge density of the receptor protein by ion exchange chromatography.
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Beaumont K, Fanestil DD. Physicochemical properties of type I corticosteroid receptors from rat brain. JOURNAL OF STEROID BIOCHEMISTRY 1986; 24:513-7. [PMID: 3009992 DOI: 10.1016/0022-4731(86)90113-5] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/03/2023]
Abstract
[3H]Aldosterone binds with high affinity to Type I corticosteroid receptors in cytosols from adrenalectomized rat forebrains. Physicochemical parameters of these receptors were determined in the presence of molybdate, which stabilized receptors and maintained them in a presumably untransformed state. The Stokes' radius of the molybdate-stabilized receptor was 8.1 nm, as determined by gel filtration on Sephacryl S-300. Its sedimentation coefficient was 9.1S in linear sucrose density gradients. The receptor is asymmetric, with an axial ratio of 8-10 and an apparent mol. wt of 303,000 dalton. The [3H]aldosterone-receptor complex is anionic and elutes from DEAE-Trisacryl in a single peak with a maximum at 160 mM KCl. Exposure to heat or salt in the absence of molybdate, conditions which transform other steroid receptors to smaller DNA-binding forms, causes marked instability of the [3H]aldosterone-receptor complex. The [3H]aldosterone-binding protein of rat forebrain, which displays the binding characteristics of a renal Type I (mineralocorticoid) receptor, is similar in size, shape and charge to the molybdate-stabilized oligomeric forms of other steroid hormone receptors.
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Lazar G, Agarwal MK. Physiological action and receptor binding of a newly synthesized and novel antiglucocorticoid. Biochem Biophys Res Commun 1986; 134:44-50. [PMID: 3947332 DOI: 10.1016/0006-291x(86)90524-3] [Citation(s) in RCA: 17] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/08/2023]
Abstract
RU 38486, a newly synthesized molecule, reversed glucocorticoid mediated enzyme induction and gluconeogenesis in the liver, and RNA synthesis in rat thymocytes. The transfer of radiolabelled dexamethasone from the cytoplasm to the nucleus was also opposed by RU 38486 in intact thymocytes. Although RU 38486 saturated the same molecular species of the receptor as the hormone in the liver, differences seemed to appear when thymus was taken into account. Along with the ongoing clinical trials, an important new tool thus appears at hand to understand and harness the molecular action of glucocorticoid hormones in mammalian systems.
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Lazar G, Agarwal MK. Evidence for an antagonist specific receptor that does not bind mineralocorticoid agonists. Biochem Biophys Res Commun 1986; 134:261-5. [PMID: 3004430 DOI: 10.1016/0006-291x(86)90556-5] [Citation(s) in RCA: 15] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/03/2023]
Abstract
Kinetics of association--dissociation, competition and chromatography on two different resins, all revealed the presence of a new binding site which: specifically accepts 7-alpha-propyl spirolactone (3H-RU-26752), has little affinity for aldosterone, is present only in the target tissue (rat kidney), and is wanting in a non-target organ (liver). The presence of such sites could explain syndromes of mineralocorticoid excess where even trace amounts of an unusual aldosterone analogue, with little affinity for the classical mineralocorticoid receptor, can nevertheless produce hypertension through the intervention of an entirely new and abundant receptor system. This new molecule thus forms a novel tool to understand the nature and function of the soluble mineralocorticoid receptor in target organs.
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Nichols NR, Nguyen HH, Meyer WJ. Physical separation of aortic corticoid receptors with type I and type II specificities. JOURNAL OF STEROID BIOCHEMISTRY 1985; 22:577-82. [PMID: 2989617 DOI: 10.1016/0022-4731(85)90208-0] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/03/2023]
Abstract
Previous gel filtration binding assay studies indicated that rat vascular smooth muscle cells contained corticoid receptor I and corticoid receptor II sites which could be distinguished on the basis of their relative affinities for aldosterone and dexamethasone. Ion-exchange chromatography experiments were designed to separate the two sites for further studies on their physical characteristics and role in vascular smooth muscle cell physiology. Cultured aortic cells were incubated with 5-10 nM 3H steroid alone or in the presence of 10-fold non-radioactive steroid competitor for 30 min at 37 degrees C. Following cell lysis, total cellular protein-bound steroid was isolated using Sephadex G-25 and applied to a DEAE-cellulose ion-exchange column. Three peaks of radioactivity were eluted using a 1-200 mM sodium phosphate gradient: peak I (30-38 mM), peak II (52-64 mM), and peak III (92-102 mM). Peaks I and II contained 60% of the eluted radioactivity and exhibited the same steroid specificity as corticoid receptor II sites (dexamethasone greater than aldosterone). Peak III contained 40% of the eluted radioactivity and exhibited the same steroid specificity as corticoid receptor I sites (aldosterone greater than dexamethasone). These studies support the binding assay data on steroid specificity and relative proportion of type I and II sites. They also document the existence of type I and II corticoid receptors with different physicochemical characteristics in rat aortic smooth muscle cells.
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Hacha R, Palem-Vliers M, Fredericq E. Activation of cytosol aldosterone receptors in rat kidney. ARCHIVES INTERNATIONALES DE PHYSIOLOGIE ET DE BIOCHIMIE 1985; 93:49-58. [PMID: 2409944 DOI: 10.3109/13813458509104515] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/31/2022]
Abstract
Cytosolic aldosterone-protein complexes are isolated from rat kidney slices after incubation with [3H]aldosterone and dexamethasone. Activated and unactivated forms of the complex are characterized by gel electrophoresis and hydroxyapatite chromatography after incubation at 4 degrees C and 25 degrees C respectively. It is found that the activated form reaches a maximum after 30 min at 25 degrees C and can be separated as an homogeneous peak by electrophoresis. Intermediate forms can also be identified. In the presence of 10 mM ATP, activation immediately occurs at 4 degrees C and is almost complete. In the presence of 10 mM molybdate, the activation is strongly enhanced and the increase in activated form may be about fifteen-fold whether molybdate is added during kidney homogenization or just before incubation at 25 degrees C. On the other hand molybdate reduces to one third the binding of the aldosterone-receptor complexes to nuclei. In the presence of the steroid RU 26988 which is a pure glucocorticoid, experiments done on aldosterone-receptors complexes and their binding to nuclei are confirmed. This proves that aldosterone is specific for mineralocorticoid sites. The general pattern of the mineralocorticoid receptor activation is discussed and its resemblance to the case of other steroid hormones is emphasized.
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Agarwal MK, Paillard J, Philippe M. Evidence for an unusual multifunctional protoreceptor in hormone action. EXPERIENTIA 1980; 36:1010-2. [PMID: 7192217 DOI: 10.1007/bf01953853] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/23/2023]
Abstract
Contrary to the techniques of mere association, column chromatography has revealed a 'protoreceptor' that accepts aldosterone agonists and antagonists only in the physiological target, the kidney, and is absent in non-targets, liver and serum; it is furthermore different from the aldosterone specific receptor in renal cytosol.
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Agarwal MK, Sekiya S, Lazar G. Search for antiglucocorticoid activity in rat liver in vivo. RESEARCH IN EXPERIMENTAL MEDICINE. ZEITSCHRIFT FUR DIE GESAMTE EXPERIMENTELLE MEDIZIN EINSCHLIESSLICH EXPERIMENTELLER CHIRURGIE 1979; 176:181-92. [PMID: 44749 DOI: 10.1007/bf01851757] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/12/2022]
Abstract
Estradiol and testosterone both lowered endogenous liver glycogen and at 20-fold higher doses impaired triamcinolone acetonide mediated glyconeogenesis in adult adrenalectomized male rats. Neither steroid influenced liver tyrosine transaminase although tryptophan pyrrolase activity was depressed by testosterone. Progesterone increased liver tryptophan pyrrolase but did not influence other parameters. Cortexolone did not alter either of these processes whereas cortisol induced both enzymes and, at much higher dose levels, gluconeogenesis. Binding of 3H-triamcinolone acetonide to its cytoplasmic receptor in vitro was left unaffected in presence of 20-fold greater concentration of either sex steroid but almost totally abolished by cold, homologous molecules. Similar results were obtained by 3H-cortisol except that estradiol partially competed for 3H-cortisol binding sites even at 20-fold greater concentrations of cold estradiol. Separation on DEAE-cellulose-52 and Ultrogel 44 columns revealed binding of all steroids to macromolecules of comparable physicochemical properties although the ratios of binding to the various subpopulations of the receptor were a function of the steroid in question. These results are discussed in terms of sex steroid binding to different moieties of a complex, heterogeneous, polymorphic protein rather than inhibition of binding to the active configuration acquired in presence of an inducer.
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Agarwal MK, Paillard J. Paradoxical nature of mineralocorticoid receptor antagonism by progestins. Biochem Biophys Res Commun 1979; 89:77-84. [PMID: 573122 DOI: 10.1016/0006-291x(79)90945-8] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/23/2022]
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ENDOTOXIN-GLUCOCORTICOID INTERACTIONS WITH HORMONE SPECIFIC RECEPTORS IN THE RAT. Toxins (Basel) 1978. [DOI: 10.1016/b978-0-08-022640-8.50083-4] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022] Open
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Agarwal MK, Philippe M. Heterogeneity of steroid hormone receptor in adult rat lung cytosol. BIOCHIMICA ET BIOPHYSICA ACTA 1977; 500:42-8. [PMID: 922039 DOI: 10.1016/0304-4165(77)90044-7] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/24/2022]
Abstract
Chromatography on cellulose DEAE-52 columns revealed that the glucocorticoid receptor for rat lung cytosol consisted of a component in the 0.001 M prewash, revealed with synthetic steroids and natural mineralocorticoids, a second component eluted with 0.04 M PO4, labelled with triamcinolone, dexamethasone, and a third moiety in the 0.06 M PO4 region, evident with natural glucocorticoids (corticosterone, cortisol) as well as mineralocorticoids (aldosterone, deoxycorticosterone). The third component coeluted with rat blood serum transcortin in double labelled experiments. Rate lung was devoid of another component in the 0.02 M PO4 found in rat liver supernate and of the mineralocorticoid receptor evident only in rat kidney. Chromatography on Sephadex G-200 columns revealed a shift of radioactivity from a higher to a lower molecular weight region in the presence of 0.4 M KCl. Collectively, these studies indicate the subunit nature of the lung receptor as evidenced in most tissues hitherto tested. Moreover, polymorphism within a given subunit component can not be revealed by competition alone, as attempted by others, but can be revealed under selected conditions of physical separation.
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Agarwal MK, Coupry F. Antigluconeogenic activity of gonadal steroid analogues in relation to liver glucocorticoid--receptor binding. FEBS Lett 1977; 82:172-4. [PMID: 913585 DOI: 10.1016/0014-5793(77)80577-2] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/24/2022]
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Agarwal MK, Coupry F, Philippe M. Physiological activity and receptor binding of 9 alpha fluorohydrocortisone. Biochem Biophys Res Commun 1977; 78:747-53. [PMID: 907708 DOI: 10.1016/0006-291x(77)90242-x] [Citation(s) in RCA: 15] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/24/2022]
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Agarwal MK. Analysis of rat serum transcortin-steroid hormone association by column chromatography. Arch Biochem Biophys 1977; 180:140-5. [PMID: 856038 DOI: 10.1016/0003-9861(77)90017-0] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/24/2022]
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Agarwal MK. Alteration in corticoid-receptor subpopulations in response to stress in the rat. BIOCHEMICAL MEDICINE 1977; 17:193-201. [PMID: 856175 DOI: 10.1016/0006-2944(77)90024-2] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/24/2022]
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Agarwal M. Physicochemical comparison of the glucocorticoid receptor from various tissues in the rat. ACTA ACUST UNITED AC 1977. [DOI: 10.1016/0020-711x(77)90120-3] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/27/2022]
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Agarwal M. Further characterization and subunit nature of mineralo- and gluco-steroid receptors from rat liver and kidney. ACTA ACUST UNITED AC 1977. [DOI: 10.1016/0020-711x(77)90059-3] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
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Agarwal MK. Evidence that natural vs synthetic steroid hormones bind to physicochemically distinct cellular receptors. Biochem Biophys Res Commun 1976; 73:767-72. [PMID: 1008886 DOI: 10.1016/0006-291x(76)90875-5] [Citation(s) in RCA: 17] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/25/2022]
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25
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Agarwal MK. Differential binding to renal receptor subpopulations as an explanation of mineralocorticoid agonist action. FEBS Lett 1976; 67:260-3. [PMID: 964358 DOI: 10.1016/0014-5793(76)80542-x] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/25/2022]
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Agarwal MK. Chromatographic conditions in the expression of corticosteroid receptor specificity. EXPERIENTIA 1976; 32:531-3. [PMID: 178529 DOI: 10.1007/bf01920840] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/13/2022]
Abstract
It is shown that cytosol preparations bound with various concentrations of a steroid are necessary to reveal physicochemically distinct, heterogeneous and polymorphic receptors present in the hormone specific target organ, that these cannot be fully appreciated in one-shot experiments at suboptimal steroids levels, and that they escape detection by equilibrium binding and Scatchard analysis alone.
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Agarwal MK. Identification and properties of renal mineralocorticoid receptors in relation to glucocorticoid binders in rat liver and kidney. Biochem J 1976; 154:567-75. [PMID: 182121 PMCID: PMC1172757 DOI: 10.1042/bj1540567] [Citation(s) in RCA: 16] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/13/2022]
Abstract
The binding of the natural mineralocorticoid aldosterone and the glucocorticoid corticosterone to macromolecules in rat liver and kidney cytoplasmic fractions was compared by various chromatographic procedures. Equilibration of kidney cytosol with 10nM-aldosterone, either alone or in the presence of a competing steroid, was ideal for ionexchange chromatography of DEAE-cellulose DE-52, and revealed the presence of four sorts of binding components. One of these, eluted in the 0.001M-phosphate pre-wash, and another, less abundant, forming a peak at 0.006M-phosphate, did not bind corticosterone at equimolar concentrations, and appear to constitute the mineralocorticoid-specific 'MR' receptor in rat kidney. They could not be detected in the liver. Radioactivity eluted in the 0.02 and 0.06M-phosphate regions on DEAE-cellulose DE-52 appears to be due to [3H]aldosterone binding to glucocorticoid-specific 'GR' receptors and to transcortin respectively, since labelling was greater with corticosterone even at 10 nM than with the mineralocorticoid at 100nM and since [14C]corticosterone bound to blood serum transcortin was always co-chromatographed in the 0.06M-phosphate region. These two components appear to be identical with those in the liver and could be labelled maximally only by 100nM-corticosterone. The separation between specific mineralo- and glucocorticoid-binding species was less clear when chromatography was attempted on DEAE-Sephadex A-50 columns, possibly because of disaggregation into subunits in the presence of the high KC1 concentrations required for elution. Competitive binding followed by filtration through Sephadex G-200 gel indicated that cellular MR binders, unlike GR receptors, exist mostly as high-molecular-weight aggregates, although both appear to exhibit a comparable monomeric molecular weight of approx. 67000.
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Baulieu EE, Atger M, Best-Belpomme M, Corvol P, Courvalin JC, Mester J, Milgrom E, Robel P, Rochefort H, De Catalogne D. Steroid hormone receptors. VITAMINS AND HORMONES 1976; 33:649-736. [PMID: 180682 DOI: 10.1016/s0083-6729(08)60974-7] [Citation(s) in RCA: 118] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/13/2022]
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Agarwal MK. Human liver glucocorticoid receptors are similar to those in rat liver. THE SCIENCE OF NATURE - NATURWISSENSCHAFTEN 1976; 63:50. [PMID: 175298 DOI: 10.1007/bf00768697] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/13/2022]
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