Showing papers on "Hydroxysteroid dehydrogenase published in 1981"
TL;DR: Eight strains of Clostridium absonum grown in the presence of deoxycholate contained both NADP-dependent 7α- and 7β-hydroxysteroid dehydrogenase activities, and it is concluded that the enzymes are bile salt-inducible.
70 citations
TL;DR: The influence of metabolism on the binding of E2 to the receptor is demonstrated and the elevated enzymatic activity present in secretory endometrium also accounts for the relatively lower concentration of [3H]E2 and the increased [3 H]estrone to [3h]E 2 ratio in the superfused tissue.
Abstract: Specimens of proliferative and secretory endometrium which differ in the levels of 17β-estradiol dehydro-genase activity, were superfused with mixtures of[3H]estradiol ([3 H]E2) and [3H]ethynyl estradiol ([3H]EE) in the presence and absence of diethylstilbestrol. Concentrations of labeled E2, EE, and estrone were measured in homogenates and in nuclei isolated from the superfused tissues. The relative proportions of [3H]EE and [3H]E2 bound to nuclear receptor were much higher in secretory than in proliferative endometrium. Since EE binds to the estrogen receptor but is not a substrate for 17β-estradiol dehydrogenase, these results demonstrate the influence ofmetabolism on the binding of E2 to the receptor. The elevated enzymatic activity present in secretory endometrium also accounts for the relatively lower concentration of [3H]E2 and the increased [3H]estrone to [3H]E2 ratio in the superfused tissue.
43 citations
TL;DR: The HSD activity was significantly lost after incubation with these enzymes, especially with phospholipase A2, and detergents, indicating that HSD is tightly associated with the particulate components and the activity is stabilized by binding to the membrane.
39 citations
TL;DR: It is concluded that considerable error can be caused by this contaminating malate dehydrogenase activity, especially in the case of low bile acid concentration in the sample.
17 citations
TL;DR: It is confirmed that the enzyme catalyzes the reversible hydrogenation of C23, C24 and C26 3-oxo bile acids with a 1:1 stoichiometry and may be involved in the biosynthesis of lithocholic acid from cholesterol through 3 alpha-hydroxy-5-cholen-24-oic acid.
Abstract: Rat liver cytosol was previously shown to contain at least three NADPH-dependent enzymes which catalyze the hydrogenation of chloral hydrate. Two of them had previously been shown to catalyze the hydrogenation of long-chain aliphatic and aromatic aldehydes or aromatic ketones in addition to halogenated acetaldehydes. The present paper demonstrates that one of these enzymes also catalyzes the reversible hydrogenation of 3-oxosteroids to 3 alpha-hydroxysteroids. We confirmed that the enzyme catalyzes the reversible hydrogenation of C23, C24 and C26 3-oxo bile acids with a 1:1 stoichiometry. The substitution at C-12 with a hydroxyl group markedly decreased the reaction rate, and the rate of dehydrogenation of C20, C23, C26, C24, and C25 bile acids decreased in the descending order. In general, the conjugation with glycine or taurine increased the reaction rate, while the replacement of the terminal carboxyl group of the C24 compound with an isobutyl group markedly decreased it. 3 alpha-Hydroxy bile acids with A/B trans configuration were also preferable substrates for the enzyme, although the reaction rate was relatively low compared with that of those with A/B cis configuration. The enzyme may be involved in the biosynthesis of lithocholic acid from cholesterol through 3 alpha-hydroxy-5-cholen-24-oic acid, which was proposed by Mitropoulos and Myant (Mitropoulos & Myant (1967), Biochem. J. 103, 472--479).
17 citations
TL;DR: The activity of 17β‐hydroxysteroid dehydrogenase was assayed in various tissues microdissected from the freeze‐dried human skin of fourteen subjects, except that the scalp epidermis showed much the same activity as the hair follicle.
Abstract: SUMMARY
The activity of 17β-hydroxysteroid dehydrogenase (17β-HSD) was assayed in various tissues microdissected from the freeze-dried human skin of fourteen subjects. The apocrine sweat gland, sebaceous gland and hair follicle possessed a high activity of 17β-HSD. The enzyme activity was negligible in the epidermis, except that the scalp epidermis showed much the same activity as the hair follicle. The dermis showed variable activity because of contamination with other components.
14 citations
Journal Article•
TL;DR: Investigation of tissue rich in presumed steroid producing cells taken from the brook lamprey during metamorphosis found evidence for hydroxysteroid dehydrogenase activity was obtained from presumed adrenocortical tissue, ovarian and testicular homogenates.
Abstract: Pronephric, opisthonephric, ovarian, and testicular tissue rich in presumed steroid producing cells taken from the brook lamprey during metamorphosis was investigated by histochemical and spectrophotometric methods. Histochemical results seemed to provide evidence for hydroxysteroid dehydrogenase activity using pregnenolone as substrate. Spectrophotometric evidence for hydroxysteroid dehydrogenase activity was obtained from presumed adrenocortical tissue, ovarian and testicular homogenates using pregnenolone, dehydroepiandrosterone, androsterone, and 3 beta, 17 beta-dihydroxy-5 alpha-androstane as substrates.
13 citations
13 citations
TL;DR: According to the zymographic analysis, this enzyme catalyzed oxidation of testosterone to androstenedione in the presence of NADP + but did not significantly convert androst-5-ene-3β,17β-diol to dehydroepiandrosterone.
11 citations
Journal Article•
9 citations
Patent•
08 Apr 1981
TL;DR: A reagent for the estimation of hydroxysteroids in serum comprising a coenzyme therefor, diaphorase, a tetrazolium salt and an inhibitor of non-steroidal hydroxyacid dehydrogenases is presented in this paper.
Abstract: A reagent for the estimation of hydroxysteroids in serum comprising a hydroxysteroid dehydrogenase, a coenzyme therefor, diaphorase, a tetrazolium salt and an inhibitor of non-steroidal hydroxyacid dehydrogenases, the said reagent being substantially free from hydroxysteroids and other serum components as well as a blank reagent for use in conjunction therewith in which the hydroxysteroid dehydrogenase is omitted.
TL;DR: It appears that an initial redox potential of less than −160 mV (achieved by autoclaving in the presence of dithiothreitol, dithioerythritol or cysteine) is important in the production of this enzyme.
Abstract: The production of 12 alpha-hydroxysteroid dehydrogenase of Clostridium group P strain C48-50 was optimized when the organism was grown in the presence of 2% fructose and 0.1% dithiothreitol. It appears that an initial redox potential of less than -160 mV (achieved by autoclaving in the presence of dithiothreitol, dithioerythritol or cysteine) is important in the production of this enzyme.
TL;DR: It is proposed that the geometry of the steroid binding site is such as to allow for compounds such as C18 and C19 17β-hydroxysteroids to bind but that a minimum size is required for tight binding, consistent with previous observations on human placental 17 β-Hydroxysteroid dehydrogenase and estrogen receptor.
TL;DR: Preparative disc-gel electrophoresis was useful to rapidly (3 days) effect a 15-fold enrichment of the estradiol-17β dehydrogenase specific activity from “heat-treated cytosol”.
Journal Article•
TL;DR: On the basis of previous investigations it is concluded that the androgen dependency of the enzyme activity of male Chbb:THOM rats has been bred into this strain in the period 1974–1977.
Abstract: 1. 1. The effect of prepuberal gonadectomy of Sprague-Dawley/NIH/HAN rats on cytoplasmic 17β-hydroxysteroid dehydrogenase was examined on day 30, 45, 60, 75, 90 and 105 of life. 2. 2. The activity in male rats was not significantly affected by gonadectomy, whereas the activity in females showed an age-dependent oestrogen dependency. 3. 3. This age-dependent oestrogen dependency could also be demonstrated in 5α-dihydrotestosterone treated intact females. 4. 4. Cytoplasmic 17β-hydroxysteroid dehydrogenase activity of female Chbb:THOM rats also showed an age-dependent oestrogen dependency, whereas the enzyme activity of male rats of this strain showed a distinct androgen dependency absent in Sprague-Dawley/NIH/HAN rats. 5. 5. On the basis of previous investigations it is concluded that the androgen dependency of the enzyme activity of male Chbb:THOM rats has been bred into this strain in the period 1974–1977.