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Query: UMLS:C0338671 (Steroids)
 9,479 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

Derivatives of estrone were prepared and linked to bovine serum albumin or its methyl-esterified form to produce immunogens which were effective in raising antisera to estrone sulfate. The most effective was estrone-3-methylphosphonothioate, electrostatically complexed with methylated bovine serum albumin. The ionically combined hapten functioned as an antigenic determinant as do covalently bound haptens when administered to sheep in emulsions with Freund's complete adjuvant. Estrone-3-phosphate covalently or electrostatically linked to bovine serum albumin also produced antisera reactive to estrone sulfate. Estrone sulfate itself, after electrostatically complexing to methylated bovine serum albumin and administration with Freund's complete adjuvant to sheep, was ineffective in producing antisera. The sera which had workable titres to estrone sulfate showed considerable cross-reaction with free estrone but was otherwise highly specific with little or no reaction with other steroid sulfates, glucosiduronates or other free steroids. Radioimmunoassay curves using [6,7-3H]-estrone sulfate were highly sensitive and were effective in the range of 5-250 pg estrone sulfate.
Steroids 1979 May
PMID:Antisera reactive directly to estrone sulfate. 8 81

Estrone glucosiduronate, 17beta-estradiol-3-glucosiduronate, 17beta-estradiol-17-glucosiduronate and estriol-16alpha-glucosiduronate have been biosynthesized in substantial yield by incubation of radioactive estrone, 17beta-estradiol, estriol and uridine diphosphoglucosiduronic acid with rhesus monkey liver homogenates. The metabolites were characterized by chromatography on Celite and DEAE-Sephadex, enzyme hydrolysis, derivative formation and crystallization to constant specific activity. The percent conversion to 17beta-estradiol-17-glucosiduronate from 17beta-estradiol ranged between 56-71%; from estrone, the conversion was 49-54%. Other metabolites formed from estradiol were estrone glucosiduronate (12-21%) and 17beta-estradiol-3-glucosiduronate(5-12%). The same metabolites derived from estrone accounted for 18-28% and 10-14% respectively. After estriol incubation, more than 90% of the steroid was converted to estriol-16alpha-glucosiduronate with no detectable estriol-3-glucosiduronate. This report represents the first time that 17beta-estradiol-17-glucosiduronate has been reported as a metabolite in the rhesus monkey and this is the only known species which forms 17beta-estradiol-17-glucosiduronate as the predominant metabolite of either estrone or estradiol in vitro. Rhesus monkey liver is similar to the human and baboon in that it metabolizes estriol exclusively to estriol-16-glucosiduronate.
Steroids 1977 Jan
PMID:Estrogen metabolism in nonhuman primates. I. In vitro biosynthesis of estrogen glucosiduronates in rhesus monkey liver. 19 Jul 39

A cloned cell line of human choriocarcinoma was evaluated as a model of human placental oestrogen production. Oestrone formation from dehydroepiandrosterone (D), D-sulphate (DS) or 4-androstenedione (A) was less than or equal to 5% of oestradiol-17beta (Oe2) formation. Oe2 formation from D and A was similar (100-150 pmole/h/10(7) cells); that from DS was 10 times less. Omitting serum from the medium increased Oe2 yield from DS 4-fold; addition of albumin restored these yields to control values (P greater than 0.05, t-test), presumably by binding DS. N6,O2'-dibutyryl-adenosine 3',5'-cyclic monophosphoric acid and theophylline treatment for 72 h stimulated (P less than 0.01) Oe2 formation from D (36%), DS (66%) and A (183%). In intact cells, sulphatase activity, Oe2 formation from D and Oe2 formation from DS equalled those in homogenates (P greater than 0.05) but Oe2 formation from D was greater than that from DS in both systems (P less than 0.001), indicating a deficiency of sulphatase relative to subsequent enzymes of oestrogen synthesis. Steroids, at concentrations previously shown to inhibit placental sulphatase or 3beta-hydroxysteroid dehydrogenase, did not inhibit choriocarcinoma enzymes. Except for its relative sulphatase deficiency and insusceptibility of oestrogen synthesizing enzymes to steroid inhibitors, choriocarcinoma appears to be a useful model of placental oestrogen synthesis.
 ...
PMID:Oestrogen formation from C19 precursors in human choriocarcinoma in culture. 19 Aug 43

Changes in levels of sex steroids and gonadotropins were measured in 16 normal prepubertal and 15 pubertal girls prior to and after a 3 hour infusion of 100 microgrm synthetic gonadotropin releasing hormone (Gn-RH). Plasa estradiol (E2) concentrations rose significantly (p less than 0.02) from 29.7 +/- 4.6 (SE) pg/ml in the basal period to to 46.8 +/- 7.1 at the end of the infusion in the pubertal girls but were unchanged in the prepubertal girls. Estrone (E1), progesterone (P), 17-HYDROXYPROGESTERONE (17OHP), TESTOSTERONE (T), DIHYDROTESTOSTERONE (DHT), and androstenedione (A), dehydroepiandrosterone (DHA) and dehydroepiandrosterone sulfate (DHAS) levels were not altered in either maturity group. Basal plasma E2, E1, T, DHT, DHA and DHAS concentrations significantly correlated with the releasable pool of LH evoked by Gn-RH from the pituitary gonadotropes. We conclude: 1) The ovary is not highly and rapidly responsive to transient elevations of endogenous gonadotropin, and 2) Adrenal androgens may to some extent modulate the maturation of the hypothalamic-pituitary-gonadal system, at least as reflected by the pituitary response to exogenous Gn-RH.
Steroids 1977 Jul
PMID:Effect of an infusion of Gn-RH upon levels of sex hormones in prepubertal and pubertal girls: evidence for relative ovarian insensitivity. 33 74

Studies show that premenopausal women have much lower levels of available cytoplasmic estrogen receptors than postmenopausal women. This study evaluates the levels of estradiol and estrone in tumor tissue cytosols of 11 premenopausal and 20 postmenopausal women, and relates these to estrogen receptors and 17B-hydroxysteroid dehydrogenase activity of the tumor samples. Estrone and estradiol levels were measured using highly specific antiestrodiol and antiestrone antisera supplied by the National Institutes of Health. The results show that tumor cytosol estradiol content is significantly higher in the premenopausal group than in the postmenopausal group. Endogenous tumor estrone, however, did not differ significantly in the pre-and postmenopausal groups. Higher levels of estradiol were noted in the ER (estrogen receptor)+premenopausal than in the ER- premenopausal patients. Significant lower levels were observed in the ER-postmenopausal than the ER+postmenopausal patients. These differences may be due in part to the tight binding of estradiol in ER+premenopausal group and the high 17B-hydroxysteroid dehydrogenase activity in the ER-postmenopausal tumors. These findings indicate that false negative results of assays in the premenopausal women is not related to the saturation of receptor sites by endogenous estrogens. Although the role of high levels of 17B-hydroxysteroid dehydrogenase in ER negative tumor is not clear, this enzyme, along with other steroid metabolizing enzymes, may be useful in controlling active steroids which affect the pathogenesis of mammary tumors.
Steroids 1979 Aug
PMID:Relationship between estrogen receptors, 17 beta-hydroxysteroid dehydrogenase and estrogen content in human breast cancer. 49 63

[4(-14C)]Estrone was injected intramuscularly into two mature laying Rhode Island Red hens. Radioactive steroids and steroid conjugates recovered from the urine on Amberlite XAD-2 columns were fractionated on columns (100 cm) of DEAE-Sephadex A-25 by NaC1 gradients. The presence of the following were confirmed, the figures in brackets indicating average proportions as per cent of total radioactivity recovered after Sephadex column chromatography:-the 3-beta-glucuronides of estrone (10.9) and of estradiol-17alpha plus estradiol-17beta(9.8): the 17-beta-glucuronides of estradiol-17alpha plus estradiol-17beta (2.1); the 3-sulfates of estrone (14.5) and of estradiol-17alpha plus estradiol-17beta(27.4); and the disulfates of estradiol-17alpha plus estradiol-17beta (2.3). The following additional conjugates were identified:-a beta-glucuronide of 16-epiestriol (0.2) and a beta-glucuronide of 16-keto-estradiol-17beta (0.2); the 3-sulfates of 16-epiestriol (1.4), of 17-epiestriol (0.9), of 16,17-epiestriol (0.7), of 16-keto-estradiol-17beta (1.1), and of 2-methoxyestrone (0.7). Some evidence was obtained for the presence of 16,17-epoxy-estratrienol-3-sulfate (1.9).
Steroids
PMID:Steroid estrogen conjugates in hens' urine II. Identifications of some minor conversion products of intramuscularly injected [4(-14C)]estrone. 70 21

[4--14C] Estrone was injected intramuscularly into six laying hens. Fifty minutes later the hens were exsanguinated. The plasmas were examined for conjugates of radioactive phenolic steroids by recovery on columns of Amberlite XAD-2 or by extraction with tetrahydrofuran followed by chromatography on a column of DEAE-Sephadex A-25 in a gradient of NaCl. The biggest Sephadex chromatographic fraction (50,4% of total) contained about 42% of its radioactivity as estradiol-17alpha-3-sulfate and 18% as estradiol-17beta-3-sulfate and the remaining 40% was identified tentatively as estradiol-17alpha-17-sulfate plus a small proportion of estradiol-17beta-17-sulfate. The second biggest Sephadex chromatographic fraction (12.7% of total) was a mixture of conjugates not further identified. Minor fractions identified comprised estrone-beta-glucuronide (2.8%), estradiol-17alpha-3-beta-glucuronide (2.8%), estradiol-17beta-3-beta-glucuronide (2.3%) and estrone sulfate (6.0%). Evidence was obtained for the presence of small proportions of estradiol-17alpha disulfate and estradiol-17beta disulfate.
Steroids 1975 May
PMID:Identifications of radioactive steroid estrogen conjugates in blood plasma of laying hens after intramuscular injection of (4--14C)-estrone. 114 86

The synthesis of estrogen methyl ethers by extractive alkylation is described. The rapid method involves estrogen in aqueous base extracted as an ion pair with the tetrahexylammonium ion into methylene chloride where irreversible alkylation (extractive alkylation) by methyl iodide occurs. Gas chromatography and mass spectrometry were used for identification of the methylated products. Estrone and estradiol were easily 3-0-methylated whereas estriol gave a dimethylated product. Methylation of 2-hydroxyestrone was possible after dissolving the compound in methyl iodide-methylene chloride with tetrahexylammonium hydroxide present, before the addition of sodium hydroxide.
Steroids 1976 Apr
PMID:Synthesis of estrogen methyl ethers by extractive alkylation. 127 97

Because intratissue levels of estrogens may be more important for the understanding of the endocrine status of an organ than are peripheral plasma levels, the concentrations of estrone and estradiol have been measured in normal and pathological breast and uterine specimens. Some breast tumors were collected in countries with differences in incidence and natural history of the disease. In other samples the subcellular distribution of the steroids was studied. Estrone levels did show much less variation than estradiol levels. Not related to estrogen receptors, estradiol levels were higher in uterine than in breast tissues. Also, the subcellular distribution observed could not be explained by changes in receptors. Malignant breast tumors of premenopausal and postmenopausal women contained similar amounts of estradiol. Unexplained large differences were found in the intratissue estradiol levels obtained in different countries.
Steroids
PMID:Estrogens in tissues: uptake from the peripheral circulation or local production. 350 65

Infusions of isotopically labeled [3H] androstenedione with measurement of [3H] estrone in normal breast and breast tumor tissue have been carried out in an attempt to determine the contribution that aromatization makes to the estrogen content of breast tissues. After infusion of [3H] androstenedione for 12h there was significant uptake of this steroid by normal breast and breast tumors. [3H] Estrone was detected in all samples of normal breast tissue examined so far but not in all tumors. Aromatase activity when measured in vitro was found to be higher in breast tumors than in fat next to the tumor or normal breast fat. Studies in which we have examined the effect of epidermal growth factor on aromatase activity in cultured breast adipose tissue suggests that the response may be influenced by a subject's menopausal status. Results from these preliminary studies suggest that the aromatization of androgens may make a significant contribution towards the estrogen content of some breast tumors and that growth factors may also be involved in regulating aromatase activity.
Steroids
PMID:Aromatase activity in normal breast and breast tumor tissues: in vivo and in vitro studies. 350 63


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