Gene/Protein Disease Symptom Drug Enzyme Compound
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Query: UMLS:C0338671 (Steroids)
 9,479 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

The properties and physical characteristics of a steroid binding component present in the immature (7 to 35 day) rat were investigated and found to be different from those of the 17 beta-estradiol receptor in the mature rat testis. These properties include a binding capacity of 483 fmol estradiol/mg protein, a Ka at equilibrium of 4.23 x 10(7)M-1, and broad steroid specificity as shown by interaction with several steroids; no binding was observed with diethylstilbestrol. The component, found in blood and several tissues including the testis, migrated as a 4.6S peak on sucrose gradients. This 4.6S component, which interacted with an anti-alphafetoprotein antiserum, decreased with age and was not detectable in the testis after day 21 or in the serum after day 25. These data suggest that this component is alphafetoprotein. Ontogenic appearance of the testicular cytoplasmic 17 beta-estradiol receptor in the developing rat was further elucidated. Sucrose gradient sedimentation analysis of cytosols revealed an 8S binding component that was first detectable at 23 days. Specific binding (fmol [3H]-estradiol/testis) was relatively low in neonates, rose to 59 fmol during the third week, and increased dramatically to 333 fmol at 7 weeks; binding rose only gradually after maturity. The receptor was tissue specific and steroid specificity studies demonstrated that only diethylstilbestrol and other estrogens were effective in competing with 17 beta-estradiol for binding sites. The Ka at equilibrium was determined as 3 x 10(10)M-1 and the binding sites were saturable in an in vitro system. The receptor did not interact with anti-alphafetoprotein antiserum as indicated by sucrose gradient studies. These data demonstrate the developmental appearance of the testicular cytoplasmic estradiol receptor in the immature rat.
Steroids 1979 Oct
PMID:Characterization of estrogen binding in the developing rat testis. Ontogeny of the testicular cytoplasmic estrogen receptor. 9 32

We have identified receptors for glucocorticoids, progestins, and androgens in a human breast tumor cell line (MCF-7) known to have estrogen receptor. Sucrose density gradients show that MCF-7 cytosol contains approximately 100 fm/mg protein estradiol (E2-3H) receptor, more than 300 fm/mg protein progesterone receptor (measured with R5020-3H), about 40 fm/mg protein 5alpha-dihydrotestosterone (5alpha-DHT-3H) receptor, and 800 fm/mg glucocorticoid receptor (measured with dexamethasone-3H). Dissociation constants obtained by Scatchard analyses were approximately 0.6 x 10(-10)M (E2), 1 x 10(-9)M (R5020), 2.8 x 10(-10)M (5alpha-DHT) and 8 x 10(-9)M (dexamethasone). No cross competition was found for estrogen receptor, but progestins competed for androgen and glucocorticoid binding. The androgen, but not the glucocorticoid, partially competed for R5020 binding to progesterone receptor. This first demonstration of 4 classes of steroid receptors in human breast cancer means that MCF-7 may be an excellent in vitro model for studying the mechanism of tumor response to endocrine therapy as well as the complex relationships between binding and biological actions of these hormones.
Steroids 1975 Dec
PMID:MCF-7; a human breast cancer cell line with estrogen, androgen, progesterone, and glucocorticoid receptors. 17 27

The present investigation was undertaken to compare the binding affinities (Ka) of the ring B unsaturated equine estrogens (equilin [Eq], equilenin [Eqn], 17 beta-dihydroequilin [17 beta-Eq], 17 beta-dihydroequilenin [17 beta-Eqn], 17 alpha-dihydroequilin [17 alpha-Eq], and17 alpha-dihydroequilenin [17 alpha-Eqn]) and the classic estrogens (estrone [E1], 17 beta-estradiol [17 beta-E2], and 17 alpha-estradiol [17 alpha-E2]) for estrogen receptors in human endometrium and rat uterus. In both species, the ring B unsaturated estrogens bind with cytosol and nuclear receptors with high affinity (Ka x 10(9) M-1). The relative binding affinities of these estrogens were measured by determining the amount of unlabeled estrogen required to reduce by 50% the specific binding of [3H]17 beta-Eq to endometrial cytosol receptors. The order of activity found was 17 beta-Eq greater than 17 beta-E2 greater than 17 beta-Eqn greater than E1 greater than Eq greater than 17 alpha-Eq greater than 17 alpha-E2 greater than 17 alpha-Eqn greater than Eqn. Essentially the same order of activity was observed when the apparent affinity constants of these estrogens for human and rat cytosol and nuclear receptors were determined by a competitive (inhibition) binding assay. Sucrose density gradient analysis indicated that these estrogens form protein complexes with cytosol and nuclear preparation that sediment at approximately 8S and 4S, respectively. The affinity constants for 17 beta-Eq were approximately two- to six-fold higher than E2 in both species. In a rat uterotropic assay, all nine estrogens were uterotropic. These data indicate that all ring B unsaturated estrogens present in conjugated equine estrogen preparations are biologically active and they express their biologic effects in the human endometrium by mechanisms similar to those described for the classic estrogens.
Steroids 1991 Apr
PMID:Interaction of ring B unsaturated estrogens with estrogen receptors of human endometrium and rat uterus. 187 86

The effects of sucrose on androgen binding to its receptor were investigated. Sucrose decreased the rate of thermal inactivation of unoccupied and occupied androgen receptor (AR) and the rates of [3H]5 alpha-dihydrotestosterone [( 3H]DHT) dissociation from both activated and nonactivated AR complexes. Binding of [3H]DHT to AR in vivo, or in intact cells at 37 degrees C, caused reduction of [3H]DHT dissociation from cytosolic and nuclear complexes, as compared to in vitro labeled receptor complexes. Further, exposure of these complexes to sucrose at 0 degrees C caused an additional reduction of dissociation rates. Thus, the decrease of [3H]DHT dissociation induced by sucrose is independent of the reaction that reduces DHT dissociation from activated and transformed AR. Sucrose also reduced the ability of mersalyl acid to inactivate AR complexes. This effect of sucrose was markedly diminished in the presence of 2M urea. Sucrose did not significantly affect the association rate, sedimentation properties, or nuclear binding ability of AR complexes, but it did decrease the equilibrium dissociation constant. Other monosaccharides and disaccharides also stabilized AR. These data suggest that sucrose induces conformational changes in the steroid binding domain of androgen receptor, thereby reducing the rates of inactivation, steroid dissociation, and the accessibility of sulfhydryl groups to mersalyl.
Steroids
PMID:Modulation of steroid affinity for the androgen receptor by sucrose. 277 67

The binding characteristics of (3H)7 alpha,17 alpha-dimethyl-19-nortestosterone [3H)DMNT) to progesterone receptors (PgR) of calf uterine tissue cytosol were determined and compared to those of the synthetic progestins (3H)ORG2058 and (3H)R5020. Scatchard plot analysis of the equilibrium binding data showed that (3H)DMNT binds to calf uterine PgR with a KD of 2.35 +/- 1.1 nM. This value is slightly higher than that of (3H)R5020 (KD = 1.16 +/- 0.4 nM) and (3H)ORG2058 (KD = 1.04 +/- 0.65 nM). Analysis of dissociation kinetics showed that (3H)DMNT dissociates much more rapidly from the receptor than the other two ligands. Competition experiments showed that ORG2058 has a lower inhibition constant (Ki) than DMNT. Sucrose density gradient (SDG) analysis of PgR showed that (3H)ORG2058-PgR complexes sediment as 8S, (3H)R5020-PgR complexes sediment as 8S and 4S, and (3H)DMNT-PgR complexes sediment as 8S entities along with dissociated (3H)steroid. These data suggest that (3H)DMNT binds to PgR with lower affinity than (3H)ORG2058 and (3H)R5020. The number of binding sites detected with (3H)DMNT are significantly lower than those measured with (3H)ORG2058.
Steroids
PMID:Binding of (3H)7 alpha,17 alpha-dimethyl-19-nortestosterone (mibolerone) to progesterone receptors: comparison with binding of (3H)R5020 and (3H)ORG2058. 356 84

Zona fasciculata-reticularis subcellular structures were implicated in corticosterone transport and secretion by noting changes in subcellular corticosterone during a 30-min period following ACTH stimulation. Six decapsulated adrenal homogenate subcellular fractions separated by gradient centrifugation were characterized cytochemically and morphologically. Predominant components in each of six fractions were: floating lipid droplets, 0.125 M sucrose (no organelles), cytosol (0.25 M sucrose supernatant with 0.25-1.2 micron electron dense granules), microsomes (interface between 0.5 M and 1.1 M sucrose layers), mitochondria (boundary between 1.1 M and 2.2 M sucrose layers) and nuclei (centrifuge pellet). Whole glands and most subcellular fractions showed peak corticosterone levels 10 to 15, and 30 min after stimulation. Sucrose and cytosolic fractions contained about 75% of the total corticosterone, responded to stimulation most significantly, and were rich in protein. In these two fractions only cytosol contained structures; these consisted of 0.15-1.2 micron electron dense granules.
Steroids 1984 Aug
PMID:Extraction of corticosterone from cell homogenates and subcellular fractions of the rat adrenal cortex. II. ACTH-induced changes in subcellular corticosterone. 610 Mar 42

We previously suggested [Steroids 33, (1979) 3; Steroids 37, (1981) 6] that cultured genital skin fibroblasts should prove useful for screening of potential antiandrogens in human and living target cells. "Serenoa repens" lipidic extract (S.R.E.) was recently reported (Br. J. Pharmacol., in press) to inhibit androgen action in animals. The present investigation was designed to study the antiandrogenicity of this compound in human cells: we therefore analyzed the effects of S.R.E. on the intracellular conversion of testosterone (T) to 5 alpha-reduced derivatives, and we investigated interaction of S.R.E. with the intracellular androgen-receptor complex. Since the chemical structure of the active component of S.R.E. is still unknown, results are expressed in U/ml (one unit is defined as the amount of S.R.E. required to inhibit 50% of the specific binding (IC50) of [3H]1881 to rat prostate cytosol). S.R.E. at different dilutions (5.7 to 28.6 U/ml) is added to culture media containing [3H]T or [3H]dihydrotestosterone (DHT) and incubated at 37 degrees C with cultured fibroblasts. 28.6 U/ml S.R.E. significantly alters the formation of DHT and strongly inhibits 3 ketosteroid reductase mediated conversion of DHT to 5 alpha-androstane-3 alpha, 17 beta-diol, characterized radiochemically by thin-layer chromatography. S.R.E. is a good competitor for the whole cell androgen receptor: 7.1 U/ml S.R.E. gives 50% inhibition of the binding of 2 X 10(-9) M [3H]DHT to its receptor. Competitive binding assays after cell fractionation indicate that S.R.E. is less potent in nuclear than in cytosol receptors. Sucrose gradient centrifugation of the radioactive cell lysate of fibroblasts demonstrates that 28.6 U/ml S.R.E. abolishes 70% of the 3.6 S receptor-complex radioactive peak. The present studies show that S.R.E. inhibits 5 alpha-reductase, 3-ketosteroid reductase and receptor binding of androgens in cultured human foreskin fibroblasts. As the search for the ideal antiandrogen continues, S.R.E. appears to be a new type of antiandrogenic compound as therapeutics for the treatment of benign prostatic hypertrophy, hirsutism and so forth.
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PMID:Inhibition of androgen metabolism and binding by a liposterolic extract of "Serenoa repens B" in human foreskin fibroblasts. 670 34

This article describes a Seven Sinful Sisters and Smart Solutions (FIVE S) concept, which lists seven contributory factors of diabetes, and seven potential solutions to help prevent its spread. The Seven Sinful Sisters include Sugar, Salt, Saturated fat, Spirits (alcohol), Sitting time (sedentary life style), Steroids (including other drugs) and Stress. Seven Smart salutogenic Solutions are use of Self-restraint, Small size portions, Spices (nutrition -based remedies, including sugar and salt substitutes), Slimnastics (a synonym for aerobic exercise), high Spirit (a positive attitude), health Sleep/Siesta, and enjoyment of Sunday (or Stress management).
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PMID:Seven Sinful Sisters: Seven Smart Solutions to Stop Diabetes. 3041 Jan 62