Gene/Protein Disease Symptom Drug Enzyme Compound
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Query: UNIPROT:P06889 (Mol)
 630,302 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

The metabolism of equilin sulfate was determined in female dogs receiving 2.5 mg/kg of [3H]equilin sulfate alone or in a preparation that contained all the components that are present in the conjugated equine estrogen product Premarin. The pharmacokinetic parameters of total radioactivity indicated that the drug is rapidly absorbed and it has a moderate half-life in plasma. The total radioactivity in plasma following administration of [3H]equilin sulfate as part of a mixture of conjugated equine estrogens had significantly lower peak concentration (Cmax), a lower area under the curve (AUC), a longer terminal half-life (t1/2) and a longer mean residence time (MRT) than when [3H]equilin sulfate was given alone, indicating that the other components in the conjugated equine estrogen preparation altered the pharmacokinetics of equilin sulfate. An average of 26.7 +/- 4.4% of the administered radioactive dose was excreted in urine of dogs receiving [3H]equilin sulfate. Again, a significantly lower percentage (21.4 +/- 6.3%, P = 0.023) was eliminated in urine of dogs receiving [3H]equilin sulfate in the conjugated equine estrogen preparation, indicating that the absorption of equilin sulfate was perhaps altered by the other components in the conjugated equine estrogen preparation. Metabolite profiles of plasma and urine were similar. Equilin, equilenin, 17 beta-dihydroequilenin, 17 beta-dihydroequilin, 17 alpha-dihydroequilenin and 17 alpha-dihydroequilin were present in both matrices. 17 beta-Dihydroequilin and equilin were the two major chromatographic peaks in plasma samples. 17 beta-Dihydroequilenin and 17 beta-dihydroequilin were the major metabolites in urine. In conclusion, following oral administration of [3H]equilin sulfate to dogs, the radioactivity is rapidly absorbed. The disposition of equilin sulfate is altered by the other components that are present in the conjugated equine estrogen preparation Premarin. The reduction of the 17-keto group and aromatization of ring-B are the major metabolic pathways of equilin in the dog.
J Steroid Biochem Mol Biol 1995 Nov
PMID:Metabolism of equilin sulfate in the dog. 749 8

Equine umbilicus was cannulated in utero and a series of cord plasma samples removed for analysis. After steroid extraction and derivatisation, gas chromatographic-mass spectrometric (GC-MS) analysis demonstrated large differences in steroid content between the plasma samples obtained from the umbilical artery and vein, the blood supplies leading to and from the placental surface, respectively. 3Beta-hydroxy-5,7-androstadien-17-one, dehydroepiandrosterone, pregnenolone, 3beta-hydroxy-5alpha-pregnan-20-one, 5-pregnene-3beta,20beta-diol and 5beta-pregnane-3beta,20beta-diol were identified as major constituents in extracts from umbilical arterial plasma samples, mostly as unconjugated steroids. Together with 5alpha-pregnane-3,20-dione, these steroids were identified in extracts from umbilical venous plasma samples but at significantly reduced levels to those determined in arterial plasma samples. Oestradiol-17alpha, dihydroequilin-17alpha and dihydroequilenin-17alpha were identified in extracts (mostly sulphate-conjugated) from both umbilical arterial and venous plasma samples, much larger amounts being detected in the plasma sampled from, rather than to, the placental surface. Equilin, equilenin, oestrone, oestradiol-17beta, dihydroequilin-17beta and dihydroequilenin-17beta were not detected in the present studies. Isomers of 5(10)-oestrene-3,17beta-diol together with 5(10),7-oestradiene-3,17beta-diol and its possible oxidative artifact, 5(10),7,9-oestratriene-3,17beta-diol, were tentatively identified only in sulphate-conjugated extracts from umbilical venous plasma samples. No glucuronic acid-conjugated steroids could be detected. The implications of this work in the elucidation of the biosynthetic pathways leading to both the formation of oestrogens and C18 neutral steroids at the placental surface are discussed.
J Steroid Biochem Mol Biol 1999 Mar
PMID:Cannulation in situ of equine umbilicus. Identification by gas chromatography-mass spectrometry (GC-MS) of differences in steroid content between arterial and venous supplies to and from the placental surface. 1041 37

In order to determine the structure-effect relationship in the induction of centrosome disintegrity (abnormality of gamma-tubulin signals) and multipolar spindles in a cultured fibroblast cell line V79 by steroidal estrogens, the activities of various estrogens and their derivatives were investigated. Induction of centrosome disintegrity by estrogens was specific in cells in the mitotic phase and was not observed in interphase cells. The centrosome disintegrity induced 24 h after exposure to estrogens was accompanied by the appearance of multinucleated cells, but the microtubule network was organized. The rank order of potency of estrogens in inducing mitotic phase-specific centrosome disintegrity and multipolar spindles was as follows: 2-methoxyestradiol>dihydroequilin 3-methyl ether=equilin 3-methyl ether>17alpha-estradiol>17beta-estradiol 3-methyl ether=17beta-estradiol>dihydroequilin>estrone 3-methyl ether. Equilin and estrone were not effective in causing centrosome disintegrity. These results suggest that the 17-hydroxyl group, irrespective of whether it is the sterically alpha or beta form, is necessary for estradiol and dihydroequilin to cause centrosome disintegrity and that O-methylation at the C-3 position was effective for equilin and dihydroequilin in enhancing the centrosome abnormality. 2-Methoxyestradiol was the most potent inducer of the centrosome disintegrity among the tested compounds and caused the induction of multiple signals of gamma-tubulin, including more than five signals.
J Steroid Biochem Mol Biol 2001 Aug
PMID:Structure-effect relationship in the induction of mitotic phase-specific abnormality of centrosome integrity and multipolar spindles by steroidal estrogens and their derivatives in cultured mammalian cells. 1156 35