3β-Hydroxy steroid dehydrogenase activity in the mitochondria of rat adrenal homogenates

1972 ◽  
Vol 126 (5) ◽  
pp. 1057.b2-1057.b2
Keyword(s):  
Dehydrogenase Activity ◽  
Hydroxy Steroid ◽  
Steroid Dehydrogenase

scholarly journals Subcellular distribution of Δ5-3 β-hydroxy steroid dehydrogenase in the granulosa cells of the domestic fowl (Gallus domesticus)

1979 ◽  
Vol 181 (3) ◽  
pp. 685-689 ◽  
Author(s):  
D G Armstrong
Keyword(s):  
Cytochrome Oxidase ◽  
Dehydrogenase Activity ◽  
Granulosa Cells ◽  
Domestic Fowl ◽  
Subcellular Location ◽  
Mitochondrial Activity ◽  
Marker Enzyme ◽  
Postovulatory Follicle ◽  
Hydroxy Steroid ◽  
Steroid Dehydrogenase

1. The distribution of 3 beta-hydroxy steroid dehydrogenase was examined in the subcellular fractions of granulosa cells collected from the ovary of the domestic fowl. 2. 3 beta-hydroxy steroid dehydrogenase activity was observed in the mitochondrial (4000g for 20min) and microsomal (105 000g for 120min) fractions. 3. Approximately three times more 3 beta-hydroxy steroid dehydrogenase activity was associated with the cytochrome oxidase activity (a mitochondrial marker enzyme) in anteovulatory-follicle granulosa cells than with that of the postovulatory follicle. 4. Comparison of the latent properties of mitochondrial 3 beta-hydroxy steroid dehydrogenase with those of cytochrome oxidase and isocitrate dehydrogenase indicated that 3 beta-hydroxy steroid dehydrogenase is located extramitochondrially. 5. This apparent distribution of 3 beta-hydroxy steroid dehydrogenase is explained on the basis that the mitochondrial activity is either an artefact caused by a redistribution in the subcellular location of the enzyme, occurring during homogenization, or by the existence of a functionally heterogeneous endoplasmic reticulum that yields particles of widely differing sedimentation properties.

3β-HYDROXYSTEROID DEHYDROGENASE ACTIVITY IN THE HUMAN FOETAL TESTIS

1965 ◽  
Vol 48 (3) ◽  
pp. 429-438 ◽  
Author(s):  
A. H. Baillie ◽  
M. Niemi ◽  
M. Ikonen
Keyword(s):  
Dehydrogenase Activity ◽  
Substrate Binding ◽  
Interstitial Cells ◽  
List Type ◽  
Colour Reaction ◽  
Crown Rump Length ◽  
Enzyme Substrate ◽  
Free Steroid ◽  
Hydroxy Steroid ◽  
Steroid Dehydrogenase

ABSTRACT Sections of testes from nine human foetuses ranging in crown-rump length from 3.0 to 18.3 cm were incubated to determine 3β-hydroxy-steroid dehydrogenase activity histochemically with the following steroids: 3β-hydroxy-pregn-5-en-20-one (pregnenolong). 3β,17α-dihydroxy-pregn-5-en-20-one (17α-hydroxypregnenolone). 3β-hydroxy-androst-5-en-17-one (DHA). 3β,17β-dihydroxy-androst-5-ene (androstenediol). 3β-sulphoxy-pregn-5-en-20-one (pregnenolone sulphate). 3β-sulphoxy-1 7α-hydroxy-pregn-5-en-20-one (17α-hydroxy-pregnenolone sulphate) 3β-sulphoxy-androst-5-en-17-one (DHAsulphate). 3β-hydroxy-5α-androstan-17-one (epiandrosterone). Pregnenolone and DHA gave a colour reaction in the interstitium of all testes studied. 17α-hydroxypregnenolone was utilised by testes from foetuses of C-R length 8.8 cm and over, androstenediol by testes from foetuses of C-R length 6.1 cm and over. These facts are thought to support the concept of separate substrate-specific 3β-hydroxysteroid dehydrogenases in the testis. Pregnenolone sulphate was used by the interstitial cells of all testes studied but gave a stronger reaction than the free steroid. 17α-hydroxy-pregnenolone sulphate was used by all foetal testes surveyed. DHA sulphate was not well used by the interstitial cells. The utilisation of steroid sulphates in a different manner from the free steroids in this histochemical system may mean that the presence of a sulphate group affects enzyme-substrate binding or that a steroid sulphatase is involved. Intense formazan deposition followed incubation with epiandrosterone in all testes studied. This seems to imply that a δ5 configuration is not necessary for enzyme-substrate binding.

INHIBITION OF 3-BETA-HYDROXY STEROID DEHYDROGENASE ACTIVITY IN FIRST TRIMESTER HUMAN PREGNANCY WITH TRILOSTANE AND WIN 32729

1983 ◽  
Vol 19 (4) ◽  
pp. 521-532 ◽  
Author(s):  
Z. M. SPUY ◽  
D. L. JONES ◽  
C. S. W. WRIGHT ◽  
B. PIURA ◽  
D. B. PAINTIN ◽  
...  
Keyword(s):  
Dehydrogenase Activity ◽  
First Trimester ◽  
Human Pregnancy ◽  
Hydroxy Steroid ◽  
Steroid Dehydrogenase

scholarly journals Luteal 20α-hydroxy steroid dehydrogenase and the formation of Δ4-3-oxo steroids in the rat after weaning or treatment with 2-bromo-α-ergocryptine during lactation

1975 ◽  
Vol 152 (3) ◽  
pp. 445-448 ◽  
Author(s):  
R G Rodway ◽  
N J Kuhn
Keyword(s):  
Enzyme Activity ◽  
Dehydrogenase Activity ◽  
Early Lactation ◽  
Early Weaning ◽  
Increased Activity ◽  
Hydroxy Steroid ◽  
Steroid Dehydrogenase

Natural or early weaning of rat litters caused an increased activity of maternal luteal 20α-hydroxy steroid dehydrogenase and a decreased release of delta4-3-oxo steroids in vitro. 2. Compound CB-154 (2-bromo-α-ergocryptine) caused an increase of 20α-hydroxy steroid dehydrogenase activity in mid-lactation but not in early lactation. 3. Prolaction did not prevent these increases in enzyme activity.

scholarly journals Isolation and characterization of 17β-hydroxy steroid dehydrogenase from human erythrocytes

1972 ◽  
Vol 127 (4) ◽  
pp. 649-659 ◽  
Author(s):  
E. Mulder ◽  
G. J. M. Lamers-Stahlhofen ◽  
H. J. Van Der Molen
Keyword(s):  
Dehydrogenase Activity ◽  
Gel Filtration ◽  
Enzymic Activity ◽  
Hydroxyl Group ◽  
Unit Weight ◽  
Ph Optimum ◽  
Ammonium Sulphate Precipitation ◽  
Isolation And Characterization ◽  
Hydroxy Steroid ◽  
Steroid Dehydrogenase

1. The 17β-hydroxy steroid dehydrogenase was solubilized during haemolysis of erythrocytes and was isolated from the membrane-free haemolysate. Membrane preparations isolated in different ways did not contain 17β-hydroxy steroid dehydrogenase activity. The 17β-hydroxy steroid dehydrogenase activity in the haemolysate was concentrated by repeated ammonium sulphate precipitation and gel filtration on Sephadex G-150. The 17β-hydroxy steroid dehydrogenase activity of the purified preparation per unit weight of protein was 350–3000 times higher than the activity of the crude erythrocyte haemolysate. The 20α-hydroxy steroid dehydrogenase activity was lost during this purification procedure. 2. The 17β-hydroxy steroid dehydrogenase was NADP-dependent and had a pH optimum for conversion of testosterone between 8.5 and 10. For the molecular weight of the enzyme a value of 64000 was calculated from Sephadex chromatography results. 3. p-Chloromercuribenzoate inhibited the enzymic activity. The oxidative activity of the enzyme for the 17β-hydroxyl group was only partly inhibited when a large excess of 17-oxo steroids was added. The catalysing activity of the enzyme was influenced by the NADP+/NADPH ratio. The oxidation of the 17β-hydroxyl group in the presence of NADP+ proceeded faster than the reduction of the 17-oxo group with NADPH. When both reduced and oxidized cofactors were present the oxidation of the 17β-hydroxyl group was inhibited to a considerable extent. 4. The enzyme had a broad substrate specificity and not only catalysed the conversion of androstanes with a 17β-hydroxyl group, or 17-oxo group, but also the conversion oestradiol⇆oestrone. In addition the steroid conjugates dehydroepiandrosterone sulphate and oestrone sulphate were also converted. There were no indications that more than one 17β-hydroxy steroid dehydrogenase was present in the partially purified preparation.

scholarly journals Metabolism of 11-oxygenated steroids. Metabolism in vitro by preparations of liver

1968 ◽  
Vol 107 (2) ◽  
pp. 239-258 ◽  
Author(s):  
I. E. Bush ◽  
Sheila A. Hunter ◽  
R. A. Meigs
Keyword(s):  
Guinea Pig ◽  
Dehydrogenase Activity ◽  
Liver Microsomes ◽  
Competitive Inhibitor ◽  
Partial Purification ◽  
Substrate Complex ◽  
Hydroxy Steroid ◽  
Steroid Dehydrogenase

1. The isolation and partial purification of 11β-hydroxy steroid dehydrogenase from rat and guinea-pig liver microsomes has been achieved by conventional methods. 2. The efficiency of different 11-oxygenated steroids as substrates has been examined. The relative efficiencies confirm in the main the stereochemical theory of the enzyme–coenzyme–substrate complex that was proposed earlier on the basis of studies in vivo. Δ4-3-Ketones and 5α-hydrogen steroids are readily metabolized by the enzyme. 5β-Hydrogen steroids and Δ4-3-ketones with certain large α-substituents are metabolized to a limited extent or not at all. Halogen substitution in the 9α-position enhances the rate of reduction of 11-ketones but blocks the oxidation of the related 11β-ols. 3. 9α-Fluorocortisol is a competitive inhibitor of the oxidation of cortisol, but 9α-fluorocortisone is reduced at five to ten times the initial velocity of cortisone. 4. 11β-Hydroxy steroid dehydrogenase activity has been found in liver microsomes of rat, guinea pig, rabbit and calf. 5. Relative substrate efficiencies and Km values are similar in whole (debris-free) homogenates, washed microsomes and acetone-dried powders of washed microsomes. 6. A variety of conditions have been examined for the observation of 11β-hydroxy steroid dehydrogenase activity. NADP(H) is an efficient and NAD(H) a very poor coenzyme for the reaction.

A metabolic stability determination of Tetrahydrothiazolopyridine derivative a selective 11β-hydroxy steroid dehydrogenase type 1 (11β-hsd1) inhibitor

2017 ◽  
Vol 8 (3) ◽  
Author(s):  
MURUGESH KANDASAMY ◽  
MUHAMMED SALIHIN ◽  
MALLIKARJUNA RAO PICHIKA ◽  
SLAVKO KOMARNYTSKY ◽  
THIRUMURUGAN RATHINASABAPATHY
Keyword(s):  
Metabolic Stability ◽  
Hydroxy Steroid ◽  
Steroid Dehydrogenase

Changes in 3β-hydroxy-Δ5-steroid dehydrogenase activity in granulosa tissue during the ovulatory cycle of the laying hen (Gallus domesticus)

1985 ◽  
Vol 106 (3) ◽  
pp. 269-273 ◽  
Author(s):  
D. G. Armstrong
Keyword(s):  
Enzyme Activity ◽  
Dehydrogenase Activity ◽  
Domestic Fowl ◽  
Ovarian Follicle ◽  
Laying Hen ◽  
Gallus Domesticus ◽  
Ovulatory Cycle ◽  
Lh Surge ◽  
Maximal Plasma ◽  
Steroid Dehydrogenase

ABSTRACT The object of this study was to examine changes in the activity of granulosa 3β-hydroxy-Δ5-steroid dehydrogenase during the ovulatory cycle of the domestic fowl. The enzyme activity in granulosa tissue from the largest follicle increased significantly during the period 8–14 h before an expected ovulation. The increase in activity occurs before the preovulatory surge of LH and near the time of lights off. During the 4–8 h period before an ovulation, i.e. the time of maximal plasma LH concentrations, 3β-hydroxy-Δ5-steroid dehydrogenase activity decreased in granulosa tissue from the largest follicle. This observation is explained by proposing that the enzyme is inhibited by the large amounts of progesterone found in the tissue at this time. The results indicate that important biochemical changes are taking place within granulosa tissue of the largest ovarian follicle before the preovulatory LH surge. J. Endocr. (1985) 106, 269–273

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