Gene/Protein Disease Symptom Drug Enzyme Compound
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Query: EC:1.1.1.3 (HSD)
 3,464 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

3beta-hydroxysteroid dehydrogenase and NADH-ferricyanide reductase activities were localized at the ultrastructural level in amphibian interrenal (adrenocortical) cells previously fixed in a mixture of formaldehyde and glutaraldehyde. Potassium ferricyanide was used as an electron acceptor. Copper ferrocyanide deposits resulting from 3beta-HSD activity were seen in close association with the external faces of the membranes of the smooth endoplasmic reticulum. Very rare grains of precipitate appeared in mitochondrial cristae. The addition of phenazine methosulfate to the incubation medium had no effect on these localizations. The interrenal cells showed also a strong NADH-ferricyanide reductase activity. The copper ferrocyanide grains were abundant in the mitochondrial cristae and in the hyaloplasm, where they were not preferentially associated with the smooth endoplasmic reticulum.
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PMID:Electron microscopic localization of 3beta-hydroxysteroid dehydrogenase and NADH-ferricyanide reductase activities in amphibian interrenal cells. 30 25

By recording the incubation time needed for initial appearance of the red and blue formazans the reliability of the histochemical method for 3beta-HSD was investigated: 1. Prefixation of small tissue blocks with 1% W/V methanol-free formaldehyde (pH=7.2) for up to 30 min preserved morphological integrity as well as maximal enzyme activity. Moreover, the substantivity of formazans and lipids was enhanced. 2. Commercial available glutaraldehyde (pH=7.2) induced SH groups in the tissue (even at 0.1% W/V for 5 min) thereby enhancing the Nothing dehydrogenase reaction. 3. Preextraction of lipids with acetone for 20 min at -30 degree C caused no loss of activity and was an inevitable step if a reliable activity pattern had to be achieved (e.g. in interstitial cells). 4. No diffusion of enzyme was noticed within 30 min of preincubation in phosphate buffer (0.2 M, pH=7.2) at 20 degree C. 5. By using the double-section incubation method no diffusion of 3beta-HSD or rediffusion of NADH or PMSH could be noticed withn 45 min of incubation, provided that low concentrations of NAD (0.1 mg/ml) and PMS (0.003 mg/ml) were balanced against the concentration of Nitro BT (0.5 mg/ml) or Tetranitro BT (1.0mg/ml). 6. The utlity of different inhibitors of alkaline phosphomonoesterase was tested and discussed. 7. By inhibiting alkaline phosphomonoesterase with 0.1 mM of L-p-bromotetramisole or 16 mM of beta-glycerophosphate, 3beta-HSD was shown to be exclusively NAD-linked. 8. Levamisole was a potent inhibitor of NADH-tetrazolium reductase as well as 3 beta-HSD, but not of NADPH-tetrazolium reductase. 9. 3beta-HSD possess SH groups requisite for the activity as this enzyme was totally inhibited by N-ethyl maleimide. 10. Whether alcohol dehydrogenases may use steroids as substrate is discussed; It is concluded that preextraction (by acetone) and/or the use of an inhibitor of alcohol dehydrogenase (1,10-phenanthroline) has to be performed. 11. Propylene glycol was a poor solvent for all substrates and was itself an excellent substrate for alcohol dehydrogenase. 12. Specifications for the ideal solvent of steroid substrates in the histochemical practice are proposed. DMSO showed to be promising as a steroid solvent (e.g. extraction of formazans was considerably lower as compared to DMF). 13. The utilization of substrates was descending in the following order (using 1 mM and 0.1 ml/ml of either DMF or DMSO): epiandrosterone, methandriol, dehydroepiandrosterone and pregnenolone. 14. If DMSO was used as solvent for pregnenolone (but not for the other substrates tested) an evident increase of activity was recorded as compared to DMF.
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PMID:Histochemistry of 3beta-hydroxysteroid dehydrogenase in rat ovary. I. Amethodological study. 55 64

Large dietary intakes of yogurt are found to lower cholestermia in man. This effect is associated with a reduction of incorporation of radioacetate into serum cholesterol. The effect appears slowly and persists after intake of the yogurt stops suggesting that the mechanism involves the synthesis of a regulatory protein rather than an allosteric effect. The effective agent is postulated to be hydroxymethyl glutarate which inhibits the regulatory enzyme hydroxymethyl glutaryl CoA reductase (EC 1.1.1.3.4).
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PMID:A factor in yogurt which lowers cholesteremia in man. 84 78

17 beta-Hydroxysteroid dehydrogenase (17 beta HSD) deficiency is a rare cause of male pseudohermaphroditism, but is a frequent disorder among a highly inbred Arab population in the Gaza strip. Affected individuals are born and reared as females until puberty, when marked virilization occurs, leading in many cases to the spontaneous adoption of a male gender role. To investigate the mechanisms and site(s) of androgen production, we determined the gonadal and extragonadal steroid patterns in two postpubertal male pseudohermaphroditism patients, who were castrated and reared as females. Before castration, both patients had very high plasma levels of androstenedione (delta 4-A), normal or moderately low levels of testosterone (T), and significantly elevated delta 4-A/T ratios (P less than 0.01). Dihydrotestosterone (DHT) levels were normal or high, while the DHT/T ratios were lower than normal (P less than 0.01), suggesting enhanced 5 alpha-reductase activity. These abnormalities were much more severe in spermatic venous blood. 17 beta HSD deficiency was also found in the delta 5-pathway, by high dehydroepiandrosterone (DHEA) levels and very high dehydroxyepiandrosterone/delta 5-androstenediol (DHEA/delta 5-diol) ratios, and in peripheral tissue metabolites, by very high androsterone glucuronide/3 alpha-androstanediol glucuronide ratios (P less than 0.01). The estrogen pathway was also impaired (P less than 0.01), even though both estrone and estradiol levels were elevated. Gonadectomy significantly reduced all androgens and estrogens (P less than 0.01), but when compared to 42 castrated controls, both patients had lower delta 4-A and higher T levels. The delta 4-A/T ratio was lower than that in controls, indicating normal to enhanced extragonadal 17 beta HSD activity. A similar pattern was observed in the delta 5- and estrogen pathways. DHT levels were within normal limits, and 3 alpha-diol was moderately decreased. These data suggest that testicular 17 beta HSD activity is under a different genetic control from that in extragonadal tissues. Affected males lack the testicular enzyme, but their extragonadal 17 beta HSD activity is normal or enhanced. Together with enhanced 5 alpha-reductase activity, this represents a highly efficient compensatory mechanism for androgen and estrogen production after puberty.
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PMID:Mechanisms of androgen production in male pseudohermaphroditism due to 17 beta-hydroxysteroid dehydrogenase deficiency. 132 74

The hamster, a rodent possessing adrenal 17 alpha-hydroxylase activity, was used to study the effect of ACTH on the regulation of cortisol formation in vivo. The characterization of the mRNA and protein of hamster adrenal steroidogenic enzymes revealed close similarities between this animal and other mammalian species. The hamster adrenal RNA hybridized in a single band to cDNA probes for bovine adrenal P450scc, P450(17 alpha), P450c21, to mouse adrenal P450(11 beta), and to pig testis 3 beta-hydroxysteroid dehydrogenase (3 beta HSD) in the areas of 2.2, 2.0, 2.3, 2.0, and 2.1 kilobases, respectively. Immunoblotting analyses revealed the presence of single protein bands reacting with antibodies to bovine P450scc, P450c21, porcine P450(17 alpha), or human placental 3 beta HSD in the areas of 52, 55, 51, and 41 kilodaltons, respectively, whereas two protein bands were detected at 48 and 52 kilodaltons with the antibody to bovine P450(11 beta). After stimulation with ACTH injected at 5-h intervals over 20 h, plasma cortisol levels, which were already increased 2.5 h after the first injection, remained elevated for the duration of treatment and returned to control values 15 h after the last injection. The ratios of plasma cortisol to corticosterone were 1.5, 3.9, and 7 at 0, 2.5, and 5 h after the first injection and continued to rise to a value of 11 at 15 h after multiple injections. This ratio returned to control values 15 h after cessation of either the short term (one injection) or long term (five injections) treatment, indicating a control mechanism favoring cortisol formation upon ACTH stimulation. Of the adrenal enzyme systems examined, only three were directly affected by ACTH treatment. The mRNA level of 3-hydroxy-3-methylglutaryl-coenzyme-A reductase, the key precholesterol regulatory step, increased after ACTH administration within 2.5 h and remained elevated during the entire study period. ACTH provoked a rapid and sustained increase in P450scc mRNA levels, which decreased very slowly after cessation of treatment without reaching control values 30 h after the last injection. Meanwhile, ACTH treatment caused no changes in the amount of adrenal cytochrome P450scc protein during treatment and 30 h after its cessation. Therefore, we postulate that factors other than newly synthesized P450scc protein participate in the control of this rate-limiting step. The high P450scc mRNA levels observed suggest stabilization of mRNA and posttranscriptional events affecting its catabolism.(ABSTRACT TRUNCATED AT 400 WORDS)
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PMID:In vivo effects of adrenocorticotropin on hamster adrenal steroidogenic enzymes. 132 21

Primates are unique in having adrenals that secrete large amounts of the precursor sex steroids (PSS) dehydroepiandrosterone (DHEA) and especially DHEA-sulfate. The adrenal PSS require the action of 3 beta-hydroxysteroid dehydrogenase/5-ene-4 ene isomerase (3 beta-HSD), 17 beta-hydroxysteroid dehydrogenase (17 beta-HSD), 5 alpha-reductase and/or aromatase to form the androgen dihydrotestosterone (DHT) or the estrogens 17 beta-estradiol and androst-5-ene-diol. Knowing the crucial role of 3 beta-HSD and 17 beta-HSD in sex steroid biosynthesis both in classical as well as in peripheral steroidogenic tissues, we have concentrated our efforts on the elucidation of the molecular structure of these enzyme families. We have thus characterized two types of human 3 beta-HSD cDNA clones and their corresponding genes which encode deduced proteins of 371 and 372 amino acids and share 93.5% homology. Human type I 3 beta-HSD is the almost exclusive mRNA species expressed in the placenta and skin, while human type II is the predominant mRNA species in the adrenals, ovaries and testes. We have also recently elucidated the structure of three types of rat 3 beta-HSD cDNAs which all encode a 372 amino acid protein. The predicted rat type I and II 3 beta-HSD proteins expressed adrenals, gonads and adipose tissue share 94% homology while they share 80% similarity with the liver-specific type III 3 beta-HSD. Transient expression of human type I and II as well as rat type I and II 3 beta-HSD cDNAs in HeLa human cervical carcinoma cells reveals that 3 beta-ol dehydrogenase and 5-ene-4-ene isomerase activities reside within a single protein and that these cDNAs encode functional 3 beta-HSD proteins. The expressed rat type III protein possesses a unique property catalyzing selectively the reduction of 3 beta-androstane 5 alpha-steroids such as DHT. Furthermore, we have also demonstrated by site-directed mutagenesis that the lower activity of expressed rat type II compared to rat type I 3 beta-HSD protein is due to a change of four amino acid residues potentially involved in a membrane-spanning domain. In parallel, we have characterized the complete nucleotide sequence of human 17 beta-HSD cDNA clones encoding a 327 amino acid protein as well as two in tandem 17 beta-HSD genes. Two major 17 beta-HSD mRNA species have been detected in several tissues due to a tissue-specific alternative site of initiation of transcription.(ABSTRACT TRUNCATED AT 400 WORDS)
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PMID:Ontogeny and subcellular localization of 3 beta-hydroxysteroid dehydrogenase (3 beta-HSD) in the human and rat adrenal, ovary and testis. 139 Feb 95

The metabolism of testosterone in the rat ventral prostate, anterior pituitary, basal hypothalamus and amygdala was studied in vitro under the influence of vitamin B6 compounds. The influence of these compounds on the activity of 5 alpha-reductase (5 alpha-R), 3 alpha- and 17 beta-hydroxysteroid dehydrogenase (3 alpha-HSD, 17 beta-HSD) was determined for all the examined tissues. Pyridoxine hydrochloride significantly increased the activity of 5 alpha-R, 3 alpha- and 17 beta-HSD, but pyridoxal hydrochloride had an inhibitory influence on 5 alpha-R and showed no effect on 3 alpha-HSD activity at the prostate level. Male rat anterior pituitary, basal hypothalamus or amygdala incubated with pyridoxal phosphate and pyridoxal hydrochloride showed modified enzymatic activities. Pyridoxal hydrochloride showed an inhibitory effect on 5 alpha-R in the rat pituitary and basal hypothalamus as well as in the rat prostate.
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PMID:Androgen hydroxysteroid dehydrogenases under the influence of pyridoxine derivatives. 142 Dec 8

3 Alpha-hydroxysteroid dehydrogenase (3 alpha-HSD) from Pseudomonas testosteroni was shown to reduce the xenobiotic carbonyl compound metyrapone (MPON). Reversely, MPON reductase purified from mouse liver microsomes and previously characterized as aldehyde reductase, was competitively inhibited by 3 alpha-HSD steroid substrates. For MPON reduction both enzymes can use either NADH or NADPH as co-substrate. Immunoblot analysis after native and SDS gel electrophoresis of 3 alpha-HSD gave a specific crossreaction with the antibodies against the microsomal mouse liver MPON reductase pointing to structural homologies between these enzymes. In conclusion, there seem to exist structural as well as functional relationships between a mammalian liver aldehyde reductase and prokaryotic 3 alpha-HSD. Moreover, based on the molecular weights and the co-substrate specificities microsomal mouse liver MPON reductase and Pseudomonas 3 alpha-HSD seem to be members of the short-chain alcohol dehydrogenase family.
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PMID:Functional and immunological relationships between metyrapone reductase from mouse liver microsomes and 3 alpha-hydroxysteroid dehydrogenase from Pseudomonas testosteroni. 155 29

Ethylene-1,2-dimethanesulphonate (EDS) rapidly destroys Leydig cells in the rat testis, although repopulation occurs within 5-7 weeks. In this study we have examined the activity of testicular steroidogenic enzymes after Leydig cell destruction and during regeneration. This was designed to measure the contribution of cells, other than Leydig cells, to steroidogenic activity in the testis, and to determine whether changes in steroidogenic enzyme activity during Leydig cell regeneration after EDS parallel those which occur during normal Leydig cell development. The enzymes studied are those responsible for androgen synthesis and metabolism in the testis. Adult male Wistar rats (300-350 g) were injected with EDS (100 mg/kg, i.p.) and testicular steroidogenic enzyme activity was measured on days 0, 3, 7, 14, 21 and 35. On day 3, when no Leydig cells remain in the testis, cholesterol side-chain cleavage (CSCC) activity, per testis, declined to undetectable levels, while 3 beta-hydroxysteroid dehydrogenase (3 beta HSD) and 17 alpha-hydroxylase retained only 0.04 and 0.15% of control activity respectively. In contrast, 17-ketosteroid reductase (17-KSR) and 5 alpha-reductase retained 33 and 10% of control activity respectively.(ABSTRACT TRUNCATED AT 250 WORDS)
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PMID:Steroidogenic enzyme activity in the rat testis following Leydig cell destruction by ethylene-1,2-dimethanesulphonate and during subsequent Leydig cell regeneration. 166 50

An 11 beta hydroxysteroid dehydrogenase (11 beta HSD) activity has been localized in the rat kidney by a histochemical technique which links steroid metabolism with the production of a color reaction. Oxidation of 11 beta-hydroxyandrostenedione was observed in cortical distal convoluted tubules and in medullary collecting ducts. Carbenoxolone abolished staining, no reaction was obtained with androstenedione hydroxylated at the 17 or 19 position, and oxidation of 11 beta-hydroxyandrostenedione was nicotinamide-adenine dinucleotide (NAD) dependent. These results demonstrate the presence of a dehydrogenase activity separate from the nicotinamide-adenine dinucleotide phosphate (NADP)-dependent 11 beta hydroxysteroid dehydrogenase recently purified and cloned from rat liver. We have named this activity 11 beta HSD2 to distinguish it from the NADP-dependent 11 beta HSD. Histological studies showed that 11 beta HSD2 activity does not correlate with the immunocytochemical localization of the previously defined 11 beta HSD enzyme, but rather the 11 beta HSD2 activity is localized in the distal tubules of the rat kidney. In this respect 11 beta HSD2 colocalizes with the mineralocorticoid receptor. No reaction product was obtained using cortisol or corticosterone as substrate with either NAD or NADP as cofactor. Furthermore incubation of tissue sections with 11 beta androstenedione in the presence of deoxycorticosterone completely inhibited cytochemical staining. We interpret these results as evidence of 20 reductase activity which uses the reduced cofactor at the expense of the color reaction. These results support the crucial role played by an 11 beta hydroxysteroid dehydrogenase in the local protection of type I receptors in mineralocorticoid selective tissues.
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PMID:Localization of an 11 beta hydroxysteroid dehydrogenase activity to the distal nephron. Evidence for the existence of two species of dehydrogenase in the rat kidney. 172 21


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