Gene/Protein Disease Symptom Drug Enzyme Compound
Pivot Concepts: Gene/Protein Disease Symptom Drug Enzyme Compound   Target Concepts: 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)

A partial testicular defect in testosterone secretion has been documented in a pubertal male with a congenital adrenal hyperplasia due to hereditary deficiency of the delta5-isomerase-3beta-hydroxysteroid dehydrogenase enzyme complex (delta5-3beta-HSD). Diagnosis of the enzymatic defect is based on the clinical picture of ambiguous genitalia and salt-losing crisis in infancy, together with high urinary delta5-pregnenetriol and plasma dehydroepiandrosterone when the patient was taken off replacement corticoid treatment. No hormonal response to ACTH or salt deprivation was demonstrable. In addition, in vivo studies revealed a partial enzymatic defect in the testis. Although plasma testosterone was low-normal (250 ng/100 ml), plasma delta5-androstenediol was markedly elevated and rose to a greater extent than testosterone after human chorionic gonadotropin administration. In vitro testicular incubation studies suggested a testicular delta5-3beta-HSD enzyme defect with less delta4 products formed from delta5 precursors than in a control testis. Histochemical studies of the testis were also consistent with this defect. Testicular biopsy revealed spermatogenic arrest, generally diminished Leydig cells, but with focal areas of Leydig cell hyperplasia as well as benign Leydig cell hyperplasia as well as benign Leudig cell nodules within the spermatic cord. In vivo studies of steroid metabolism suggested intact peripheral or hepatic delta5-3beta-HSD activity. These studies imply that delta5-3beta-HSD activity differs in the gonad, adrenal, and peripheral organs. These findings are compatible with the concept that the enzyme complex consists of subunits and/or that enzymes in these organs are under different genetic control.
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PMID:Persistent testicular delta5-isomerase-3beta-hydroxysteroid dehydrogenase (delta5-3beta-HSD) deficiency in the delta5-3beta-HSD form of congenital adrenal hyperplasia. 16 81

A detailed physicochemical characterization of purified homoserine dehydrogenase of Rhodospirillum rubrum is presented. The enzyme has a molecular weight of 110000 and consists of two subunits of identical molecular weight of 55000. Depending on the ionic strength and protein concentration it is possible for the native enzyme to dimerize to produce an enzymatically active species of molecular weight 220000. Titrations of the native and detergent-treated enzyme with a variety of sulfhydryl reagents show 2 mol free--SH groups per 110000 g, one of which is buried in the protein interior. L-Threonine and/or high concentrations of salt can expose the buried--SH group, and this--SH group is essential for the catalytic activity of the enzyme. Two independent lines of evidence show that extensive polymerization of the enzyme caused by L-threonine and/or high concentrations of salt does not involve the formation of intermolecular disulfide bonds.
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PMID:Homoserine dehydrogenase of Rhodospirillum rubrum. Physical and chemical characterization. 41 12

A study of the ultrastructural localization of 3 beta-hydroxysteroid dehydrogenase (3 beta-HSD), 11 beta-hydroxysteroid dehydrogenase (11 beta-HSD), glucose-6-phosphate dehydrogenase (G-6-PD), beta-hydroxybutyrate dehydrogenase (beta-HBD), NADH diaphorase (NADH-D) and NADPH diaphorase (NADPH-D) in the guinea-pig testis is reported. The procedures employed included short immersion or perfusion fixation with aldehydes followed by incubation of small blocks in a tetrazolium salt or a ferricyanide medium. The effects of incubation conditions were investigated, and a reaction medium for the ultracytochemical demonstration of 11 beta-HSD is described. Using suitable controls, evidence for the specificity of the cytochemical reactions is presented. It was found that all the enzymes studied were present in both the Leydig and Sertoli cells of the guinea-pig testis and that the intracellular distribution pattern for each enzyme was independent of the cell type. Using tetrazolium salt techniques, both 3 beta-HSD and 11 beta-HSD activities were localized on or in membranes of smooth endoplasmic reticulum and within the mitochondria. With the ferricyanide techniques, G-6-PD activity was found to be associated mainly with the smooth endoplasmic reticulum membranes, while beta-HBD activity was limited to mitochondria. With both the tetrazolium salt and ferricyanide techniques, the reaction products for NADH-D and NADPH-D activities showed localizations which were similar to those observed for the steroid dehydrogenases.
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PMID:The ultrastructural localization of the enzymes related to steroid hormone metabolism in the guinea-pig testis. 42 99

The growth of Clostridium group P strain C48-50 [an anaerobe that contains 12alpha-hydroxysteroid dehydrogenase (12alpha-HSDH) in the absence of other dehydrogenases active upon bile salts] is greatly enhanced by the addition of 2.0% d-fructose or d-glucose to the growth medium. Other sugars were less effective. The production of NADP-dependent 12alpha-HSDH paralleled the growth of the organism which was optimal at 72 hr. Growth (and enzyme production) were suppressed by the addition of bile salt to the medium; the order of suppression was deoxycholate > chenodeoxycholate >> cholate; 1 mM of either of the dihydroxy-bile salts inhibited 96% of the growth and 100% of the enzyme production. Kinetic studies on cell-free preparations of 12alpha-HSDH revealed a pH optimum of 7.8 with greater linearity of NADP evolution with time occurring only at more alkaline pH values (9-10). Lineweaver-Burke plots revealed Michaelis constant (K(m)) values in the range of 3-5 x 10(-4) M for deoxycholate and its glycine and taurine conjugates, while higher values were found for cholate and conjugates (K(m) value for taurocholate was 3 x 10(-3) M). Although there was no activity with NAD, 12alpha-HSDH was shown to bind onto both NAD- and NADP-Sepharose columns, with stronger binding on the latter. The enzyme was purified 20-fold by NAD-Sepharose chromatography. The molecular weight was estimated at 100,000 by Sephadex G-200 and a series of molecular weight markers. Substrate specificity studies showed that a variety of bile salts containing 12alpha-OH groups reacted; notably, the 3alpha-sulfates of cholate and deoxycholate were nonsubstrates.-Macdonald, I. A., J. F. Jellett and D. E. Mahony. 12alpha-Hydroxysteroid dehydrogenase from Clostridium Group P strain C48-50 #29733: partial purification and characterization.
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PMID:12alpha-Hydroxysteroid dehydrogenase from Clostridium group P strain C48-50 ATCC No. 29733: partial purification and characterization. 43 63

The effects of exposure of rainbow trout (Salmo gairdneri Richardson) to three sublethal concentrations of zinc (0.248, 0.528 and 1.14 ppm) on delta 5-3 beta-hydroxysteroid dehydrogenase (delta 5-3 beta HSDH) enzyme activity in the head kidney tissue was investigated. The activity of this enzyme was localized by the reduction of a tetrazolium salt to formazan at the site of activity. Using subjective methods to indicate the degree of activity and indirectly assess the degree of corticosteroid production, the zinc-exposed rainbow trout showed a greater degree of delta 5-3 beta HSDH activity compared to the control fish. This increase in enzyme activity has been associated with the stimulation of the pituitary-interrenal axis by the noxious stress of zinc.
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PMID:The activity of delta 5-3 beta hydroxysteroid dehydrogenase enzyme in the interrenal tissue of rainbow trout (Salmo gairdneri Richardson) exposed to sublethal concentrations of zinc. 96 21

In addition to demonstrating evidences of increased sympathetic nervous system activity and marked left ventricular hypertrophy in salt-sensitive hypertensives, our group has also reported increased weight gain with salt overload in these patients. The increased weight gain suggests volume expansion, a situation already shown to increase plasma levels of a Na, K-ATPase inhibitor. Therefore, in the present study, digoxin-like factor (DLF) serum levels, spontaneous salt ingestion, nifedipine hypotensive effect, and plasma renin activity were evaluated in essential hypertensive subjects. Thirteen essential hypertensive outpatients were studied sequentially on an ad lib diet, a low salt diet (LSD = 30 mEq Na/day), and a high salt diet (HSD = LSD + 171 mmol/L NaCl/day), 1 week each. On the seventh day of LSD and HSD, DLF levels, mean blood pressure (MBP) response to nifedipine (10 mg sublingual), and plasma renin activity were measured. The MBP percent change from the seventh day of LSD to the seventh day of HSD (salt sensitivity) ranged from -13.7 to 20.9%. A positive correlation (r = 0.64, P < .01) was observed between salt sensitivity and 24-h urinary sodium excretion with an ad lib diet. The DLF serum levels correlated with the salt sensitivity both on LSD (r = 0.50, P < .05) and on HSD (r = 0.53, P < .05). Salt sensitivity was positively correlated with the difference of response to nifedipine between HSD and LSD (r = 0.78, P < .001). Plasma renin activity correlated inversely with DLF on LSD (r = -0.51, P < .05).(ABSTRACT TRUNCATED AT 250 WORDS)
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PMID:Higher salt consumption, digoxin-like factor, and nifedipine response are associated with salt sensitivity in essential hypertension. 141 33

The apparent mineralocorticoid excess syndrome of patients ingesting large amounts of licorice or its derivatives is thought to be caused by the antagonism by these compounds of the enzyme 11 beta-hydroxysteroid dehydrogenase (11 beta-HSD). 11 beta-HSD inactivates cortisol and corticosterone, allowing the more abundantly produced glucocorticoids access to the mineralocorticoid receptor (MR) in the kidney, where they act as mineralocorticoids. We have found that the infusion of both glycyrrhizic acid, an active principle of licorice, and carbenoxolone, a synthetic analogue, into a lateral ventricle of the brain [intracerebroventricular (icv)] of a rat, at a dose less than that which has an effect when infused subcutaneously, produces hypertension. Furthermore, the hypertension produced by the oral administration of carbenoxolone or glycyrrhizic acid is blocked by the icv administration of RU 28318, an MR antagonist, at a dose below that which has an effect on blood pressure when infused subcutaneously. While the oral administration caused saline polydipsia and polyuria typical of chronic systemic mineralocorticoid excess, the icv licorice derivatives produced hypertension without affecting saline appetite. Sensitizing the rats to mineralocorticoid hypertension by renal mass reduction and increasing salt consumption was not necessary for the production of hypertension. These findings provide additional evidence for a central role in blood pressure control by mineralocorticoids that is distinct from their renal effects. They also suggest that more is involved in licorice-induced hypertension than only inhibition of 11 beta-HSD.
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PMID:Central hypertensinogenic effects of glycyrrhizic acid and carbenoxolone. 147 86

The enzyme 11 beta-hydroxysteroid dehydrogenase (11-HSD) appears to be involved in mediating aldosterone specificity of otherwise nonselective type I receptors in mineralocorticoid target tissues. In the present study gene expression of 11-HSD was characterized in various tissues of the rat by use of a complementary DNA probe coding for the rat liver 11-HSD. In the liver, lung, testis, colon, heart, hippocampus, and kidney papilla a single message was observed of length approximately 1700 nucleotides (nt). In the kidney cortex/medulla, however, messenger RNA (mRNA) species were observed at 1900 nt, 1600 nt and 1500 nt, and deadenylation studies showed that the renal 1900 nt species was heterogeneous. Northern blot analysis of 11-HSD mRNA showed low levels of expression in the kidney of the neonate and much higher levels in liver and lung with expression increasing markedly in all three tissues over development. In mature rats, a low salt diet significantly elevated 11-HSD mRNA in the liver but not in other tissues. We interpret these data as evidence for the existence of a family of 11-HSD genes, and consistent with the possibility that the hepatic species may modulate occupancy of type II (classical) glucocorticoid rather than type I receptors.
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PMID:Characterization of 11 beta-hydroxysteroid dehydrogenase gene expression: identification of multiple unique forms of messenger ribonucleic acid in the rat kidney. 224 39

We studied the acute effect of oral captopril (25mg) and clonidine(300 micrograms) on blood pressure (BP) in patients with essential hypertension successively maintained on a low (LSD) and high (HSD) salt diet. Seven patients were salt sensitive (SS) and seven were salt resistant (SR). The maximal decrease in diastolic BP caused by captopril in patients on the LSD was greater in SS than SR individuals. Baseline urinary norepinephrine levels did not change from LSD to HSD (p greater than 0.05) in SS patients and decreased in SR patients (p less than 0.05). The maximal decrease in mean BP during the clonidine test was the same for both diets (p greater than 0.05) in SS patients and was lower (p less than 0.05) for the HSD in SR patients. SS patients on the HSD presented a higher decrease in systolic BP than SR patients (p less than 0.05) during the clonidine test. These data suggest overactivity of the renin-angiotensin system in SS patients on the LSD and of the sympathetic nervous system in SS patients on the HSD and that the clonidine test could be a good indicator for identifying SS and SR patients.
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PMID:Salt sensitivity in human essential hypertension: effect of renin-angiotensin and sympathetic nervous system blockade. 266 51

In these studies our goal was to solubilize the microsomal enzyme, 11 beta-hydroxysteroid dehydrogenase (11-HSD) as the first step in its purification. Enzyme was extracted from rat liver microsomes with representative detergents (Zwittergents, Tritons, modified sterols). Oxidation-reduction (O-R) ratios of extracts varied with detergent used and ranged from 0.18 (CHAPS) to 3.8 (Zwittergent 3-14) relative to a ratio of 1.7 in intact microsomes. All detergents solubilized 11-HSD using lack of sedimentation during high speed centrifugation as criterion. With Triton DF-18 and Triton X-100, optimum extraction of 11-HSD occurred in the detergent-protein ratio range of 0.1 to 0.2 O-R ratios decreased with increased Triton X-100, but were constant as Triton DF-18 was varied. The pH optimum of enzyme extraction was 9 at a detergent-protein ratio of 0.05 and 7.5-8.0 at a ratio of 0.2. Sodium chloride increased enzyme extraction by detergents; in the absence of detergent, salt extracted protein, but not enzyme. In aqueous solution at 0 degrees C or -15 degrees C, microsomal 11-oxidation activity rose within 24 h, then decreased; reductase activity consistently decreased. Oxidation and reduction activities were inversely related in the microsomal bound enzyme. No relationship between these activities appeared in detergent-solubilized enzymes. Possible mechanisms to account for the unexpected behavior of this enzyme are discussed.
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PMID:Extraction of 11 beta-hydroxysteroid dehydrogenase from rat liver microsomes by detergents. 385 94


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