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

The epididymis of adult rats metabolizes 3H 5alpha-androstane-3alpah,17beta-diol (3alpha-diol) by experiments in vitro. After incubation of tissue slices at 37 degrees C for 2 hours, 2% of the radioactivity was found in the water-soluble fraction whereas 98% was found to be ether soluble (free steroids). Further investigation of the free steroids showed the following to be present: 3alpha-diol 39.9%, DHT (17beta-hydroxy-5alpha-androstan-3-one) 33.7%, androsterone (3alpha-hydroxy-5alpha-androstan-17-one) 9.2%, 3beta-diol (5alpha-androstane-3beta,17beta-diol) 2.6%, 5alpha-A-dione (5alpha-androstan-3,17-dione) 1.1%, delta 16-3alpha-ol (5alpha-androst-16-en-3alpha-ol) 1.0%, delta16-3beta-ol (5alpha-androst-16-en-3beta-ol) 2.6%, delta 16-3-one (5alpha-androst-16-en-3-one) 2.9%, and polar compounds 3.3%. When segments of the epididymis (caput and cauda) were incubated in the same way, qualitatively similar metabolites were formed but a greater amount of 3alpha-diol was metabolized by the cauda epididymis. This increase was mainly accounted for by an increased formation of delta 16 compounds (14.3% in cauda, 4.3% in caput). This is most probably due to the presence of larger numbers of mature spermatozoa, which, as we have previously shown, form delta16 steroids from 3alpha-diol and DHT (5).
Steroids 1977 Oct
PMID:Androgen metabolism by rat epididymis. Metabolic conversion of 3H 5alpha-androstane-3alpha,17beta-diol, in vitro. 60 59

Initial excretion studies with orally administered [monoethyl-1-3H] DES demonstrated the feces to be the principal mode of elimination of DES in the C3H mouse. Metabolic studies with tritiated DES and/or [UL-14C] DES were performed with orally dosed C3H high (MTV+) and low (MTV-) titer MMTV female mice. Extraction and partitioning of the fecal radioactivity demonstrated 77 to 86% (n = 4) to be benzene soluble and the remainder H2O soluble. The principal product in the organic phase following Sephadex LH-20 and HPLC purification was DES. The aqueous phase was resolved by LH-20 into two conjugate fractions that were partially hydrolyzed by beta-glucuronidase. The principal aglycone was chromatographically identical with authentic DES. The urinary conjugates were resolved into six fractions. The four major fractions were 80% hydrolyzable with beta-glucuronidase. Two of these fractions had trans-DES as the principal aglycone, whereas the other two had a major peak similar to but not chromatographically coincident with cis-DES. In certain experiments mice were sequentially dosed with tritium (24 hr) followed by a 14C dose (24 hr). Two mice (MTV+) were also previously fed 1000 ppb DES prior to these experiments. The tritated and 14C products were combined and analyzed simultaneously. This experiment did not reveal significant differences in the metabolism due to the modes of radioactive labeling, MMTV titer, or the prior feeding of DES. The developed methodology was judged to purify quantitatively 90% or more of the DES radioactive products.
Steroids 1978 Apr
PMID:Metabolism of diethylstilbestrol in the C3H mouse: chromatographic systems for the quantitative analysis of DES metabolic products. 66 80

The metabolism of 1,2-3H-androstenedione was studied in 2 cell lines, MCF-7 (estrogen responsive) and BT-20 (estrogen nonresponsive) over 48 hrs. Water soluble and unconjugated metabolites were separated by solvent partition and the former was submitted to chromatography on Sephadex LH-20 and enzyme hydrolysis. The resulting unconjugated steroids were separated by paper chromatography and identities were established by reverse isotope dilution. The unconjugated steroids initially obtained were separated by chromatography and identified by reverse isotope dilution. About 70% of the androstenedione was metabolized by both cell lines. However, the respective conversions to conjugates by MCF-7 and BT-20 were 31% and 0.32%. In the former, glucosiduronates predominated (94%) and consisted of androsterone (55%), etiocholanolone (9.4%) and androstanediol (5alpha-androstane-3alpha,17beta-diol) (9.3%). Androsterone comprised most of the unconjugated metabolites in both cell lines. Androstanediol was found in both cell lines, 2% in MCF-7 and 12% in BT-20. Testosterone, 5alpha-androstane-3,17-dione and 3beta-hydroxy-5alpha-androstan-17-one were isolated only from MCF-7. The metabolism of 3H-estriol was studied in a similar way. Both cell lines produced about equal amounts of estriol-3-sulfate (9%) and a compound with properties of estriol-3-glucosiduronate (0.15--0.5%). The results worthy of emphasis are: 1. The far greater conjugation of androgens exhibited by the MCF-7 cell lines as compared to the BT-20 cell lines; 2. In MCF-7, the high conversion of androstenedione to etiocholanolone (glucosiduronate form), a metabolite reported to form only in liver and sebaceous cysts; 3. The possible formation in both cell lines of estriol-3-glucosiduronate, normally a metabolite of the intestine.
Steroids 1978 Dec
PMID:Steroid metabolism in human breast cancer cell lines. 73 1

The effect of estradiol-17beta (E2) on several important aspects of cholesterol metabolism were examined in the rat. Ovariectomized rats were implanted subcutaneously with 1 or 4 cm. of silastic tubing packed with E2, and were also given 2% D2O in their drinking water. The E2 diffused slowly out of the implants and the two different lengths of tubing resulted in constant E2 blood concentrations of either high (4.0 cm) or physiological (1.0 cm) levels. By measuring the rate of incorporation of deuterium into plasma cholesterol by mass spectrometry over a period of 42 days, we determined the rate constant of cholesterol synthesis and cholesterol turnover time and rate under two E2 dosage conditions. E2 treatment did not affect the rate constant of cholesterol turnover rate (mg synthesized/day) showed a dose dependent reduction with increasing doses of E2. This may be secondarily caused by E2's suppression of both food intake and subsequent weight gain; E2 treated animals are smaller and, therefore, synthesize less cholesterol per day. Additionally, E2 treated animals showed a rise in plasma cholesterol levels and in the fraction of labeled cholesterol appearing in the plasma.
Steroids 1977 Jan
PMID:Effects of estradiol-17beta on cholesterol metabolism in the rat: a study using a deuterium label and mass spectrometry. 84 14

The nature of the water-soluble products formed by incubating labelled estradiol with uterine peroxidase in the presence of H2O2 and tyrosine was examined by two-dimensional thin-layer chromatography and high voltage electrophoresis. It was shown that the steroid and amino acid were associated in a 1:2 or 1:3 ratio and evidence was provided by 3H-exchange for the interaction of tyrosine with ring A of estradiol at C-2 and C-4. The possible role of estrogen-induced peroxidase in the uterus in vivo is discussed.
Steroids 1977 Apr
PMID:Metabolism of estradiol by uterine peroxidase: nature of the water-soluble products. 86 50

Pure performylated bile acids are obtained in quantitative yield by a new formylation procedure. The procedure involves heating the bile acids in 90% formic acid containing catalytic amount of perchloric acid and then adding acetic anhydride slowly until effervescence occurs. Pure performylated bile acids are then isolated simply by diluting the reaction mixture with water. Contrary to what was believed by past investigations, the formyl groups on these compounds are quite stable to various reaction conditions. The stability and ready availability of these compounds make them more suitable candidates than their counterpart--bile acid acetates for use as starting material in various synthetic schemes, such as C-24 labeled bile acids, etc. The partial deformylation of these formates can be effected by using methanolic ammonia, sodium methoxide in methanol, or sodium hydroxide in aqueous acetone. The resultiing 3-hydroxy formyl bile acids are obtained in high yield and are the best starting materials for the synthesis of bile acids with specific modification at 3-hydroxyl group, such as the synthesis of bile acid 3-monosulfates and 3-monoglucuronides.
Steroids 1977 May
PMID:Formylated bile acids: improved synthesis, properties, and partial deformylation. 89 31

The vaginotrophic and uterotrophic activities of 1-OH-8-alpha-E2 and its acetate in comparison with E2 and E3 were assessed on the basis of the effect on weights, water/fat-and RNA/DNA-contents of mouse vagina and uterus. The multiple doses of 8 alpha-steroids or E3 sufficient to achieve a maximal effect on the vagina were not enough to stimulate the uterus fully. At various periods of time after multiple injections, 1-OH-8 alpha-E2 acetate was found to have a higher vaginotrophic potency than the uterotrophic potency, when compared with E2 as a standard. The study on the time course of organ response to 8 alpha-steroids, E2 and E3 after a single injection of daily dose, being equipotent when injected one daily for 3 days, demonstrated that 1-OH-8-alpha-E2 and E3 were less vaginotrophic and uterotrophic than E2 and had a short duration of action. 1-OH-8 alpha-E2 acetate in comparison with E2 produced a long-lasting vaginotrophic effect and an early regressing uterotrophic effect. It can be confirmed that 8 alpha-steroids, like E3, are a special type of estrogen having a high vaginotrophic activity and a low uterotrophic activity.
Steroids 1977 Aug
PMID:8 alpha-Estra-1,3,5(10)-triene-1,3, 17 beta-triol as a special type of estrogen having a high vaginotrophic activity and a low uterotrophic activity in castrated mice. 92 44

The ability to form androgen conjugates and the hormone dependency of the conjugating enzymes have been studied in the rat epididymis. Following the in vitro incubation of 3H-testosterone with epididymal slices from intact and castrated rats, the radioactivity recovered was partitioned between water and ether. Examination of the water soluble radioactivity demonstrated the presence of glucuronides and sulfates. The total radioactivity in the conjugate fraction was the same for both intact and castrated animals. However, castrated rats showed a 3-fold increase in the glucuronide fraction with a corresponding decrease in the formation of sulfates. Characterization of the ether soluble radioactivity after solvolysis of the conjugate fraction from castrated animals, showed DHT (17beta-hydroxy-5alpha-androstan-3-one) and 3alpha-diol (5alpha-andro-stane-3alpha, 17beta-diol) to be the main metabolites. After beta-glucuronidase hydrolysis of the same, only 3alpha-diol could be demonstrated at a significant level, although traces of DHT and delta16 compounds were present. Corresponding hydrolysis of the water phase from incubation of epididymis from intact rats, demonstrated a marked quantitative difference. Here approximately 40% of the conjugated aglycones consisted of delta16 compounds, whilst only about 12% was comprised of 3alpha-diol. The preferential conjugation of DHT and 3alpha-diol to a sulfate radical was demonstrated in both intact and castrated rats. Since the conjugated delta16 compounds were detected only in the epididymis from intact animals, it is possible that these are formed by the spermatozoa.
Steroids 1976 May
PMID:Androgen metabolism by rat epididymis. 4. The formation of conjugates. 94 Nov 82

Cultures of HeLa S3 cells were treated with prednisolone metasulfobenzoate (Na), a derivative of prednisolone which is readily soluble in water. The steroid induced an increase in DNase II, a lysosomal enzyme which was not used previously in enzyme induction by steroids. Alkaline phosphatase, a known inducible enzyme by other steroids and acid phosphatase, a known uninducible enzyme by other steroids, were included for comparative reasons.
Steroids 1976 Jun
PMID:Effects of prednisolone metasulfabenzoate on the induction of DNase II in comparison to alkaline phosphatase and acid phosphatase activities in cultures of HeLa S3 cells. 94 Nov 92

A simple, sensitive and reliable competitive protein binding radioassay using dog transcortin has been developed for the measurement of 11-deoxycorticosterone (DOC) in human plasma. A 1% plasma solution from dexamethasone treated male dogs served as the source of the binding protein. Sephadex LH-20 column chromatography was used for the separation of the steroid prior to assay. The method is sensitive enough to detect 50 pg of DOC. The intra- and interassay co-efficients of variation were 11.5% and 11.3% respectively. Water blanks and plasma blanks from adrenalectomized rats and humans gave negligible readings for DOC. Support for the identity of the steroid being assayed as DOC was obtained by subjecting a plasma pool to multiple radioassays using 4 different binding proteins including 2 anti-DOC antibodies. The values obtained in all 4 systems were in good agreement confirming the fact that DOC was the steroid being measured. Morning plasma DOC levels measured in 29 healthy subjects averaged 8.0 plus or minus 1.2 (S.E.) ng% in 14 males, and 8.7 plus or minus 0.9 (S.E.) ng% in 15 females (p greater than 0.3).
Steroids 1975 Jan
PMID:A competitive protein binding radioassay for deoxycorticosterone in human plasma. 111 Nov 69


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