Gene/Protein Disease Symptom Drug Enzyme Compound
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Query: UNIPROT:Q8NEX9 (reductase)
 26,410 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

Although a sulfate-reducing pathway in Escherichia coli involving free sulfite and sulfide has been suggested, it is shown that, as in Chlorella, a pathway involving bound intermediates is also present. E. coli extracts contained a sulfotransferase that transferred the sulfonyl group from a nucleosidephosphosulfate to an acceptor to form an organic thiosulfate. This enzyme was specific for adenosine 3'-phosphate 5'-phosphosulfate, did not utilize adenine 5'-phosphosulfate, and transferred to a carrier molecule that was identical with thioredoxin in molecular weight and amino acid composition. In the absence of thioredoxin, only very low levels of the transfer of the sulfo group to thiols was observed. As in Chlorella, thiosulfonate reductase activity that reduced glutathione-S-SO3- to bound sulfide could be detected. In E. coli, this enzyme used reduced nicotinamide adenine dinucleotide phosphate and Mg2+, but did not require the addition of ferredoxin or ferredoxin nicotinamide adenine dinucleotide phosphate reductase. Although in Chlorella the thiosulfonate reductase appears to be a different enzyme from the sulfite reductase, the E. coli thiosulfonate reductase and sulfite reductase may be activities of the same enzyme.
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PMID:Sulfate-reducing pathway in Escherichia coli involving bound intermediates. 0 97

The data on the activity of the enzymes of xenobiotic metabolism in peripheral blood lymphocytes point to essential disorders within the system of detoxification in patients with bronchopulmonary pathology. The necessity of cultivating cells with mitogens before measurement of the activity of the enzymes of xenobiotic metabolism of the first phase (cytochrome P-450, cytochrome C-reductase) for more precise measurement and reproducibility of the results is discussed. Study of the activity of cytosol enzymes of the second phase (glutathione-S-transferase, sulfotransferase) does not require preliminary cell cultivation. The authors emphasize the importance of studying the enzymes of xenobiotic metabolism to individualize the treatment and choose optimal drug doses.
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PMID:[The enzyme spectrum of the peripheral blood lymphocytes in patients with nonspecific lung diseases]. 385 47

Carrot foliage monoterpenes induce cytochrome P-450 up to 2.9-fold, NADPH cytochrome c (P-450) reductase up to 1.6-fold, NADPH-oxidation up to 3.8-fold, aldrin epoxidation up to 1.5-fold in southern armyworm larval midgut tissues when incorporated in their diet at 0.2% for 3 days. Stigmasterol and ergosterol did not substantially induce microsomal oxidase activities and significantly inhibited GSH S-aryltransferase activity and sulfotransferase activity. Coumarin did not substantially affect microsomal oxidase and sulfotransferase activity but is the most potent inducer of GSH S-aryltransferase activity, increasing this activity 7-fold. None of the chemicals is acutely toxic to the sixth instar larvae or affect the larval weight gain except coumarin which significantly depressed the maximal body weight attained.
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PMID:Induction by carrot allelochemicals of insecticide-metabolising enzymes in the southern armyworm (Spodoptera eridania). 614 78

Several metabolic activities in dissociated cultures of newborn mouse brain were compared to the situation in vivo. The developmental activity pattern of cerebroside-sulfotransferase, cyclic nucleotide phosphohydrolase, and beta-hydroxy-beta-methyl glutaryl-coenzyme A-reductase and the synthesis and deposition of sulfatide and cholesterol in culture were estimated. The enzyme activity patterns in vivo and in culture are the same. Since the cultures show very little myelin formation, the parallel increase of enzyme activities necessary for myelination in vivo and in culture suggest the existence of intrinsic factors regulating the biochemical differentiation. In addition, the formation of the products, determined in culture, follows the patterns of the enzyme activities. Dissociated brain cell cultures are therefore a valid model for the study of biochemical parameters related to the synthesis of brain lipids during development.
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PMID:Synthesis of lipids in mouse brain cell cultures during development. 627 83

Male albino mice were raised on diets containing less than 10 ppb selenium (Se-) or supplemented with 0.5 ppm selenium (Se+) for 6 months. In the (Se-) group total liver selenium was less than 10% of the control, liver selenium-dependent glutathione peroxidase (GSH-Px) less than 2%. The specific activities of catalase and superoxide dismutase showed essentially no differences between the dietary groups. Several phase I-related specific enzyme activities were measured in liver microsomes. No significant differences between the two animal groups were found for cytochrome P-450 and b 5 content, NADH-cytochrome b 5 reductase, as well as for aniline hydroxylation and aminopyrine dealkylation rates. In (Se-) microsomes, NADPH-cytochrome P-450 reductase activity was about half that found in (Se+) microsomes. An increase in microsomes from (Se-) mice was found for 7-ethoxycoumarine deethylation rate (460%), cytochrome P-450 hydroperoxidase activity (170%), and heme oxygenase (276%). The N-oxidation rate of the flavin-containing monooxygenase decreased by 35%, the N-demethylation rate by 50% in (Se-) animals. Stopped-flow measurements of the reduction rates of microsomal pigments did not support evidence for limitations in microsomal electron supply during selenium deficiency. Among the phase II reactions examined, sulfotransferase activity towards 4-nitrophenol was 47% of the controls in Se-deficient liver cytosols while UDP-glucuronyl transferase activity towards this substrate increased to 215%. Glutathione-S-transferase activity was much higher in (Se-) livers than in (Se+): 310% with 1,2-dichloro-4-nitrobenzene, 255% with 1-chloro-2,4-dinitrobenzene and 120% with ethacrynic acid as substrate. The data indicate that in addition to GSH-Px many other enzyme activities in mouse liver are affected by prolonged dietary selenium deficiency. These effects might be useful in assessing the severity of selenium deficiency. A microsomal selenium-dependent metabolic modulator is discussed as a possible mechanism.
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PMID:Selenium and drug metabolism--I. Multiple modulations of mouse liver enzymes. 663 74

Cerebroside-sulfotransferase (CST), creatine-phosphokinase (CPK), and 3-hydroxy-3-methylglutaroyl CoA (HMG CoA) reductase activity, protein, and DNA content were measured in an easy-to-perform organotypic culture system of newborn normal and jimpy brains. The defective sulfatide synthesis which has been shown in vivo in jimpy brains could also be demonstrated in organ cultures of jimpy mice in the form of lowered CST activity in the homogenate as well as reduced 35SO4 incorporation into 35SO4-sulfatide. HMG CoA reductase was reduced to 60% of that found in 16-day-old normal cultures, similar to the findings in vivo. DNA of jimpy cultures was significantly lower than that in normal cultures, suggesting the possibility of an arrest in the differentiation or increased cellular death of presumptive oligodendrocytes, as was found in vivo. Organ cultures of jimpy mouse brain can serve as an appropriate model for further study of the primary defect in this animal mutant.
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PMID:Abnormal metabolism of 35SO4-sulfatide in jimpy brains expressed in brain organotypic cultures. 693 89

Theophylline, a drug used in neonatology for the treatment of apnea, affects cholesterol synthesis if administered in concentrations of 10(-4) M (a concentration found in serum of treated patients) for 24 hr to dissociated brain cell cultures. The rate-limiting enzyme of cholesterol synthesis, beta-hydroxy-beta-methylglutaryl-coenzyme A reductase (EC 1.1.1.34), is lowered to 45% 48 hr after removal of theophylline. At the same time, cholesterol content of the cells is lowered to 73%. Inasmuch as the phospholipid content of the cells remains stable, the treatment changes the cholesterol phospholipid ratio. Concomitant to this effect, the activity of cerebroside-sulfotransferase (EC 2.8.2.11) is lowered to 60% of control values. We postulate that these two effects are linked to each other by means of modulation of the cerebroside-sulfotransferase activity by membrane lipids.
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PMID:Theophylline reduces the activity of cerebroside-sulfotransferase, a key enzyme in myelination, in cell cultures from newborn mouse brain. 693 24

Androsterone sulfate (Andros-S) is the most abundant 5 alpha-reduced androgen metabolite in serum. To determine whether this steroid could serve as a marker of 5 alpha-reductase activity, we developed a specific RIA, using tritiated Andros-S to assess procedural losses. Baseline serum Andros-S levels (mumol/L; mean +/- SEM) in 14 hirsute women (3.0 +/- 0.4) were not reduced by ovarian suppression with leuprolide (3.0 +/- 0.3), but were decreased by 79% with combined ovarian and adrenal suppression with leuprolide and dexamethasone. The mean Andros-S level in polycystic ovarian syndrome (3.2 +/- 0.4) and in idiopathic hirsutism (3.5 +/- 0.5) was not significantly different from levels in normal women (3.0 +/- 0.5), but were significantly greater than levels in obese women (1.7 +/- 0.3; P < 0.05). The serum concentrations of Andros-S were about 10-fold greater than those of androsterone glucuronide and 100-fold greater than those of androstanediol glucuronide. Serum Andros-S concentrations correlated strongly with dehydroepiandrosterone sulfate (R = 0.59; P < 0.001) and to a lesser degree with androstanediol glucuronide and androsterone glucuronide (R = 0.28 and 0.49, respectively). There was a weak correlation with androstenedione levels and the androstenedione response to ACTH (R = 0.38 and 0.34, respectively), and no significant correlation with serum testosterone (R = 0.19). The ratio of any of the 5 alpha-reduced products (Andros-S, androstanediol glucuronide, and androsterone glucuronide) to precursors (androstenedione and testosterone) was not increased in hirsute women, suggesting that these women did not have a generalized increase in 5 alpha-reductase activity. In conclusion, these results confirm that Andros-S is the most abundant 5 alpha-reduced androgen metabolite in serum. It is primarily, if not exclusively, of adrenal origin in hirsute women. The fact that its levels were not elevated in hirsutism, although those of other adrenal androgens and androgen metabolites (androstanediol glucuronide and androsterone glucuronide) were, suggests that variations in sulfotransferase activity or metabolic clearance of Andros-S may be important determinants of serum Andros-S levels. Although Andros-S may be a marker of systemic 5 alpha-reductase activity, there was no evidence of a generalized increase in 5 alpha-reductase activity in hirsute women. Andros-S is therefore not recommended as a marker of either adrenal androgen production or of hirsutism.
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PMID:Androsterone sulfate: physiology and clinical significance in hirsute women. 838 Jun 2

The effects of aging on the activities of drug-metabolizing enzymes and antioxidant enzymes were studied in male and female White-Footed mice (Peromyscus leucopus) at ages of 6, 8, 12, 18, 24, 30, 36, and 48 months. Male mice had significantly higher liver microsomal cytochrome P450 (P450) content and NADPH:cytochrome P450 oxidoreductase (P450 reductase) activities than females at all age groups. Many of the P450-dependent enzyme activities were also generally higher in males. Female mice showed age-dependent decreases in P450 content and the activities of P450 reductase, pentoxyresorufin O-dealkylase (PROD) and N-nitrosodimethylamine demethylase (NDMAd) in the liver from 6 to 24 months; while, the males showed an age-dependent decrease only for the liver PROD activity from 6 to 24 months. The old males (30-month old) appeared to have significantly higher activities for 6 beta-, 2 beta-, 16 alpha- and 16 beta-testosterone and androstenedione formation than the middle-aged (6- to 18-month old) and very old (48-month old) males. Females showed age-dependent decreases for the formation of 6 beta-, 2 beta-, 16 alpha- and 16 beta-testosterone in liver microsomes from 6 to 24 months. Lung microsomes from 6- and 8-month old males had much higher activities of ethoxyresorufin O-deethylase (EROD) and PROD than older males. The total NNK alpha-hydroxylation activities changed in the same pattern as lung microsomal EROD and PROD activities in both male and female mice. The activities of several phase II drug-metabolizing enzymes: glutathione S-transferase (GST), DT-diaphorase, sulfotransferase and UDP-glucuronosyl-transferase (UDPGT) did not show any significant age-dependent changes, with the possible exception that the GST activity in males decreased from 18 to 36 months. Males had about 3-fold higher UDPGT activities than females among all age groups. Glutathione peroxidase activities were drastically lower in old and very old males, and 6 to 24 months old males had significantly higher activities than the corresponding females. In females, superoxide dismutase activities decreased linearly to extremely low levels as mice aged. Catalase activities showed a tendency for increase with age in males. In conclusion, some P450-dependent activities and antioxidant enzymes, but not phase II drug-metabolizing enzymes, showed age-dependent changes; and most of these changes occur from 6 to 24 months. The demographic attributes of the White-Footed mouse are well-suited for physiological and biochemical studies of aging and can complement the more standard laboratory mouse model with its typical two year life span.
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PMID:Age- and gender-related variations in the activities of drug-metabolizing and antioxidant enzymes in the white-footed mouse (Peromyscus leucopus). 849 97

Androgens are C-19 steroids that provide major regulatory influences on male reproductive function. Testosterone, the principal androgenic steroid, is secreted by the Leydig cells of the testes. Both testosterone and its 5 alpha reduced derivative 5 alpha-dihydrotestosterone (DHT) are physiological ligands for the androgen receptor (AR). Ligand-activated AR acts as a nuclear transcription factor and mediates androgen action. AR, along with receptors for a number of C-21 steroids such as glucocorticoid, mineralocorticoid, and progesterone, share the same 15 base pair consensus element composed of 5'-GGA/TACAnnnTGTTCT-3'. Despite this cross-reactivity at the level of the DNA, physiologically, androgens regulate their target genes with a high degree of receptor specificity. Such a regulatory specificity appears to be due to multiphasic interactions involving enzymatic activation/inactivation of the steroid ligand, interaction with specific receptor-associated nuclear factors on or around the hormone response element, and differential regulation of the receptor gene expression. Conversion of testosterone to 5 alpha-dihydrotestosterone in target cells is a widespread activation mechanism that amplifies the androgenic signal. Unlike the testosterone-AR complex, DHT-activated AR has a longer half-life, and thus prolongs androgen action. Oxido-reduction of androgens by 17 beta-hydroxysteroid dehydrogenase and sulfurylation by androgen sulfotransferase are two major pathways of androgen inactivation in target cells. Prenatal deprivation of androgen action, due to mutations in either the AR or the 5 alpha-reductase gene, results in developmental abnormalities of male reproductive tissues and also cause partial or complete androgen-insensitivity syndromes. Elucidation of various molecular steps in androgen action is allowing development of improved therapeutic agents for the management of disorders of androgen action such as the prostatic hypertrophy and neoplasia.
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PMID:Androgen action. 884 82


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