Asoprisnil (J 867; benzaldehyde, 4-[(11beta, 17beta)-17-methoxy-17-(methoxymethyl)-3-oxoestra-4, 9-dien-11beta-yl]-, 1-oxime) is the prototype of a novel class 11beta-benzaldoxime-substituted selective progesterone receptor modulators (SPRMs) and the first-in-class SPRM to reach an advanced stage of clinical development for the treatment of uterine fibroids and endometriosis. This compound was selected in a drug discovery program aimed to identify progesterone receptor (PR) ligands with predominant agonist but also some antagonist activities. The screening program included a range of receptor binding studies and a hierarchy of in vivo tests.
View Article and Find Full Text PDFThe distinct roles of the two estrogen receptor (ER) isotypes, ERalpha and ERbeta, in mediating the physiological responses to estrogens are not completely understood. Although knockout animal experiments have been aiding to gain insight into estrogen signaling, additional information on the function of ERalpha and ERbeta will be provided by the application of isotype-selective ER agonists. Based on the crystal structure of the ERalpha ligand binding domain and a homology model of the ERbeta-ligand binding domain, we have designed steroidal ligands that exploit the differences in size and flexibility of the two ligand binding cavities.
View Article and Find Full Text PDFThis study was performed to evaluate and compare the effects of estradiol sulfamate (J995) and estradiol (E2) on the hepatic levels of the estrogen receptor (ER) and its mRNA, in ovariectomized (OVX) and OVX+hypophysectomized (OVXHX) female rats and to study the effects on the liver-derived serum compounds angiotensin I, triglycerides, high-density lipoprotein (HDL) and cholesterol. ER concentrations were determined using ligand-binding assay (LBA) and enzyme immuno assay (EIA), and the mRNA levels using solution hybridization. The rats were treated orally (p.
View Article and Find Full Text PDFSulfamate substitution (-O-SO2-NH2) at carbon atom 3 of the steroid skeleton leads to orally active prodrugs of estrogens with much higher systemic, but lower hepatic, estrogenic activity than their parent steroids. This dissociation is achieved by first passage through the liver in erythrocytes, followed by systemic hydrolysis which releases the 'parent' estrogen. In the rat, orally administered tritiated estradiol sulfamate, unlike estradiol, appears in the circulation at high concentrations.
View Article and Find Full Text PDFThe majority of data regarding biological effects of estrogens is based on studies in male rats or ovariectomized (Ovx) female rats. Therefore, in this study, the effects of estradiol treatment on the regulation of the hepatic estrogen receptor and the level of circulating angiotensinogen were examined in the intact female rat. The data were compared with that of the hypophysectomized (Hx) rat.
View Article and Find Full Text PDFJ Steroid Biochem Mol Biol
October 2000
Estradiol sulfamate (J995), estradiol-17beta with a substituted sulfamate group in position 3, has much higher systemic estrogenic activity after oral administration than 17beta-estradiol (E2) due to reduced hepatic metabolism of the drug. The lower dose necessary for achievement of adequate systemic estrogenic effects results in a substantial reduction of otherwise commonly observed hepatic side-effects. This makes J995 a strong candidate as an estrogen suitable for oral administration.
View Article and Find Full Text PDFJ Steroid Biochem Mol Biol
December 1995
Oral therapy with natural or synthetic estrogens, like ethinylestradiol, suffers from low, suboptimally defined bioavailability and excess hepatic estrogen actions. N,N-alkylated and non-alkylated sulfamates of ethinylestradiol, estradiol and estrone overcome these deficiencies. Ovariectomized Wistar rats (n = 6-7/group) were orally treated for 7 days, and killed on day 8, plasma was gained on days 0, 4, and 8.
View Article and Find Full Text PDFPlasma dehydroepiandrosterone (DHEA) and DHEA sulfate levels were determined by an enzyme immunoassay in male and female Sprague-Dawley rats fed a diet containing 0.6% or 0.3% DHEA.
View Article and Find Full Text PDFFollowing oral administration of 2 mg of dienogest (17 alpha-cyanomethyl-17 beta-hydroxy-4,9-estradien-3-one) to female volunteers, the dienogest concentration courses in plasma and saliva were determined by means of a specific radioimmunoassay (RIA). Three different procedures of the plasma sample preparation prior to the RIA were compared. The dienogest RIA was directly applied to saliva.
View Article and Find Full Text PDFFor the radioimmunological determination (RIA) of the progestagen dienogest (1, 17 alpha-Cyanomethyl-17 beta-hydroxy-estra-4,9-dien-3-one) in plasma three methods of sample preparation were tested and compared: Extraction of plasma samples with dichlormethane (I), binding of plasma dienogest to an antiserum added; removal of non-bound steroids by means of activated charcoal, extraction of dienogest using dichlormethane (II), using the RIA without extraction of plasma samples after partial precipitation of proteins by means of ammonium sulphate (III). The reliability of the dienogest-RIA is, characterized by a limit of detection of 3.2 pg (I, III) and 5 pg (II) per tube, respectively, by "within-assay"- and "between-assay" variation coefficients of 3 to 5% and 3 to 9%, respectively, in parallel determinations and by a high rate of recovery of dienogest (greater than 90%) added to plasma.
View Article and Find Full Text PDFIn order to develop a radioimmunoassay for the new progestagen dienogest (STS 557, 17 alpha-cyanomethyl-17 beta-hydroxy-estra-4,9-dien-3-one), bovine serum albumin (BSA) conjugates of STS 557-3-carboxymethyloxime and of STS 557-11-hemisuccinate were synthesized as antigens for the production of antisera. It was proved that an excess of isobutylchlorocarbonate in the coupling reaction using the "mixed anhydride method" results in an acylation of free NH2-groups in the BSA. By the immunization of rabbits with the STS 557-antigen-antisera of high specificity and affinity to STS 557 were produced.
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