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:1.6.99.3 (diaphorase)
5,903 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

Haemonchus contortus, incubated in 10 micrograms/ml and 50 micrograms/ml concentrations of Nilzan and albendazole in Tyrode solution were stained for histoenzymatic demonstration of various phosphatases, oxido-reductases and esterases. The intestine showed major alterations after drug treatments. The alkaline phosphatases (AkPase), adenosine triphosphatase (ATPase), glucose-6-phosphatase, succinic dehydrogenase (SDH), glutamate dehydrogenase (GDH), reduced nicotinamide adenine dinucleotide phosphate diaphorase and reduced nicotinamide adenine dinucleotide diaphorase showed a decreased activity in intestine after Nilzan treatment, whereas lactic dehydrogenase (LDH), glucose-6-phosphate dehydrogenase (G-6-PD) and monoamine oxidase resisted increased reaction. The albendazole treatment resulted in altered distribution pattern of the AkPase, ATPase, SDH, and GDH; while LDH, G-6-PD, and non-specific esterases exhibited slightly enhanced activity in the epithelium. The functional significance of these changes has been fully discussed.
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PMID:Effect of Nilzan and albendazole on the absorptive surfaces of Haemonchus contortus (Nematoda)--a histoenzymic study. 196 79

A NADPH cytochrome c oxidoreductase purified from membranes of rabbit peritoneal neutrophil was shown to behave as the NADPH dehydrogenase component of the O2- generating oxidase complex. A photoactivable derivative of NADP+, azido nitrophenyl-gamma-aminobutyryl NADP+ (NAP4-NADP+), was synthesized in its labeled [3H] form and used to photolabel the NADPH cytochrome c reductase at different stages of the purification procedure. Control assays performed in dim light indicated that the reduced form of NADP4-NADP+ generated by reduction with glucose-6-phosphate and glucose-6-phosphate dehydrogenase was oxidized at virtually the same rate as NADPH. Upon photoirradiation of the purified reductase in the presence of [3H]NAP4-NADP+ and subsequent separation of the photolabeled species by sodium dodecyl sulfate polyacrylamide gel electrophoresis, radioactivity was found to be present predominantly in a protein band with a molecular mass of 77-kDa and accessorily in bands of 67-kDa and 57-kDa. Evidence is provided that the 67-kDa and 57-kDa proteins arose from the 77-kDa protein by proteolysis. Despite removal of part of the sequence, the proteolyzed proteins were still active in catalyzing electron transport from NADPH to cytochrome c and in binding the photoactivable derivative of NADP+.
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PMID:Characterization of multiple active forms of the NADPH dehydrogenase component of the oxidase complex from rabbit peritoneal neutrophils by photolabeling with an arylazido derivative of NADP+. 210 11

Topical application on rat oral mucosa of the chemical 4-nitroquinoline 1-oxide (4NQO) has been shown to produce squamous cell carcinomas on the posterior tongue and/or the posterior hard palate. 4NQO is broken down in vivo by a diaphorase, 4NQO reductase (E.C.1.6.99.2), to produce an active molecule believed to be responsible for carcinogenesis. It has been shown that there are higher concentrations of 4NQO reductase in oesophageal mucosa compared with elsewhere in the gastrointestinal tract. The purpose of these experiments was to compare the distribution of certain diaphorases in the oral mucosa. Samples of rat tongue and cheek epithelia were homogenized, then ultracentrifuged to provide mixed cytosol and microsome fractions from the epithelial cells. A spectrophotometer was used to measure the variation in absorbance at 340 nm of NADH consumed by reduction of 4NQO by enzymes present in the tissue extracts. A histochemical technique was used to compare the activity of NADH diaphorase, NADP diaphorase and glucose-6-phosphate dehydrogenase at different sites of the oral mucosa. Statistical analysis showed that there were significant (P less than 0.01) differences between the activities of all three enzymes at different sites of the oral mucosa. In each case, a higher activity was found at the sites of high incidence of squamous cell carcinoma. A lower activity was found at sites where carcinomas did not occur.
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PMID:A relationship found between intra-oral sites of 4NQO reductase activity and chemical carcinogenesis. 211 96

The activity of human myocardial enzymes in sudden coronary death (SCD) was quantitatively histochemically examined. The activity of succinate dehydrogenase (SDH), lactate dehydrogenase (LDH), beta-oxybutyrate dehydrogenase (beta-OBDH), alpha-glycerolphosphate dehydrogenase (alpha-GPDH), NAD-diaphorase (NAD-ase), and glucose-6-phosphate dehydrogenase (G-6-PDH) was measured on prompt autopsies (up to 3 hours of death onset). beta-OBDH and LDH showed an increase in activity in the myocardium from the subjects who had suddenly died from coronary heart disease without evident changes in the heart. In SCD in the presence of small cardiosclerosis, the activity of the enzymes characterizing the major processes of energy generation was also enhanced, which was caused by moderately severe myocardial hypertrophy. In the myocardium from the subjects who had died from coronary heart disease in the presence of large postinfarction cardiosclerosis, the activity of the enzymes was directly related to the degree of myocardial hypertrophy and the signs of chronic heart failure. As myocardial hypertrophy progressed, the enzymatic activity rose, but there were signs of chronic heart failure, it fell. The findings suggest that the changes in myocardial enzymatic activity in SCD are heterogeneous and associated with the type of prior abnormalities in the cardiovascular system.
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PMID:[Disorders of myocardial metabolism in sudden coronary death in the presence of coronary atherosclerosis: findings of quantitative histoenzymologic studies]. 221 37

Histochemical profiles were made of identified spinal motoneurons from normal adult zebrafish and from animals subjected to cordotomy or unilateral axotomy of the motor nerves. The lesions caused an increase of the myotomal area with oxidative muscle fibers. We studied the question: do changes in the myotomal muscle configuration concur with changes in the enzyme histochemical profiles of innervating motoneurons? Based on the location and size of cell somata, two categories of motoneurons are distinguished: large white (W) motoneurons that innervate the deep fast, glycolytic muscle fibers, and smaller red and intermediate (RI) motoneurons that innervate the superficial slow oxidative and intermediate muscle fibers. In normal animals, glucose-6-phosphate dehydrogenase activity is high in the large W motoneurons and relatively low in the small RI motoneurons. The reverse holds for succinate dehydrogenase activity is high in the large W motoneurons and relatively low in the small RI motoneurons. The reverse holds for succinate dehydrogenase activity. W and RI motoneurons show similar nicotinamide adenine dinucleotide diaphorase activity. Short- (2 weeks) and long- (8 weeks) term effects of lesions were studied. The results show that: (1) the 3 types of lesions lead to prolonged changes in the enzyme histochemical profiles of spinal motoneurons. The type of change depends on the type of lesion and on the type of motoneuron; (2) unilateral axotomy of the motor nerves affects the histochemical characteristics of spinal motoneurons and the myotomal muscle fiber type configuration on the ipsi- and contralateral side. The contralateral effects are conceived as adaptations to maintain a left-right symmetry in the motor output.
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PMID:Enzyme histochemical profiles of fish spinal motoneurons after cordotomy and axotomy of motor nerves. 228 25

Quantitative cytochemical techniques have been employed in a study of some of the acute effects of low doses (0.01----1 mU/liter) of TSH on the metabolism of guinea pig thyroid segments maintained in nonproliferative organ culture. The enzymes involved in the synthesis of NADP+ (NAD+ kinase), its reduction by the pentose-shunt (glucose 6-phosphate dehydrogenase), and its reoxidation both by the microsomal electron chain (diaphorase activity) and by participation in other cellular processes, have been examined. The effect of TSH on peroxidase activity has also been studied. After 10 min stimulation with TSH (1 mU/liter) there was a 60% increase in NAD+ kinase activity which preceded changes in the microsomal reoxidation of NADPH (up 33% by 30 min). There were no changes in the activity of glucose 6-phosphate dehydrogenase. There was a sustained rise in peroxidase activity which reached 129% over control after 30 min. This is the first in vitro demonstration of an acute stimulation of peroxidase and kinase activities by physiological concentrations of TSH. NADPH reoxidation after stimulation with TSH was such that the ratio of NADPH reoxidized via the microsomal respiratory pathway (diaphorase, hydrogen pathway 1) relative to that available for cytosolic utilization (hydrogen pathway 2) increased compared to the unstimulated controls. We suggest that increased NADP+ production (via NAD+ kinase activity) and the preferential shuttling of the NADPH for reoxidation via the microsomal respiratory pathway, coupled with greatly stimulated peroxidase activity, may be important regulators of the control of thyroglobulin iodination and hence thyroid hormone production.
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PMID:Acute stimulation of thyroidal NAD+ kinase, NADPH reoxidation, and peroxidase activities by physiological concentrations of thyroid stimulating hormone acting in vitro: a quantitative cytochemical study. 284 14

In a population of cultured rat liver epithelial cells transformed by 11 brief treatments with N-methyl-N'-nitro-N-nitrosoguanidine, 9% of the cells stained intensely for gamma-glutamyl transpeptidase (GGT). We have isolated from this phenotypically heterogeneous tumorigenic cell population 11 GGT-positive and 7 GGT-negative clonal subpopulations (from single cells) and have analyzed the ploidy and selected biochemical, histochemical, and growth properties of the cells in these clonal sublines. As compared to the GGT-negative strains and normal diploid rat liver epithelial cells, cells of the GGT-positive strains are larger in size, have greater DNA content, proliferate more slowly in culture, and have higher specific activities of NADH diaphorase, glucose-6-phosphate dehydrogenase, pyruvate kinase, and lactate dehydrogenase. The GGT-positive strains also show greater alteration and heterogeneity than do the GGT-negative strains in their ability to store glycogen and in their expression of lactate dehydrogenase isozymes. The results indicate that enzymatic changes commonly observed in "altered" hepatocytes in rat livers exposed to chemical carcinogens in vivo can also be produced in vitro in cultured hepatic epithelial cells by treatment with carcinogens. Moreover, treatment of a cell line with a chemical carcinogen generates a population of cells vastly heterogeneous in both their phenotypes and genotypes. Isolation of clonal subpopulations from the resulting cell line allows critical examination of the linkage and mechanistic relationship between tumorigenicity and many paratumorigenic phenotypes.
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PMID:Clonal isolation of populations of gamma-glutamyl transpeptidase-positive and -negative cells from rat liver epithelial cells chemically transformed in vitro. 286 91

Clonal subpopulations of a chemically induced tumorigenic rat liver epithelial cell line were analyzed for their cellular, biochemical, and in vitro growth properties and their tumorigenicity after injection into day-old newborn isogeneic rats. The phenotypic properties studied included DNA content; growth rate in culture; activities of gamma-glutamyl transpeptidase, NADH diaphorase, pyruvate kinase, glucose-6-phosphate dehydrogenase, and lactate dehydrogenase; ability to grow in calcium-poor medium; and ability to form colonies in soft agar. The results show that none of these phenotypes cosegregates with tumorigenicity and therefore is not reliable as a "marker" phenotype for neoplastic transformation in cultured rat liver epithelial cells. The poor correlations, either qualitatively or quantitatively, between paratumorigenic phenotypes and tumorigenicity suggest that neoplastic transformation in these cells involves a specific transforming gene locus or loci and that in vitro paratumorigenic phenotypes are merely epiphenomena of neoplastic transformation and progression. This study further reveals that the efficiency of the tumorigenicity assay of cultured rat liver epithelial cells in isogeneic newborn rats can be considerably improved by incubating the cells in medium containing only trace amounts of serum prior to transplantation into the host animals.
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PMID:Clonal analysis of tumorigenicity and paratumorigenic phenotypes in rat liver epithelial cells chemically transformed in vitro. 286 92

F344 Male rats weighting between 90 and 110 gm were given 90 ppm diethylnitrosamine in their drinking water for 5 weeks. Seven weeks after the administration of carcinogen was completed, the rats were sacrificed and sections of their livers were embedded in methacrylate. Serial sections 2 or 4 micron in thickness demonstrated the presence of gamma-glutamyl transpeptidase, acid phosphatase, adenosine triphosphatase, aldehyde dehydrogenase, alkaline phosphatase, alpha-naphthyl butyrate esterase, DT diaphorase, glucose-6-phosphate dehydrogenase, and 5'-nucleotidase activity and glycogen. The use of 4-micron sections of methacrylate-embedded tissue allows the evaluation of many more phenotypic markers in serial sections than is currently possible with frozen sections.
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PMID:Examination of enzyme-altered foci with gamma-glutamyl transpeptidase, aldehyde dehydrogenase, glucose-6-phosphate dehydrogenase, and other markers in methacrylate-embedded liver. 287 68

Experiments were undertaken to examine the ability of selenium to protect against acetaminophen-induced hepatotoxicity and to examine possible mechanisms for this protective effect. Pretreatment of male, Sprague-Dawley rats with sodium selenite (12.5 mumol Se/kg, ip) 24 hr prior to acetaminophen administration produced a significant protection against the hepatotoxic effects of acetaminophen as assessed by a decrease in the plasma appearance of alanine aminotransferase and aspartate aminotransferase activities following acetaminophen. This was accompanied by an increase in the hepatic glutathione levels in selenium-treated animals and an inhibition in the decrease in hepatic glutathione content observed in animals receiving hepatotoxic doses of acetaminophen. Selenium pretreatment decreased the in vivo covalent binding of acetaminophen metabolites to hepatic protein, but did not alter hepatic microsomal cytochrome P-450 content or NADPH cytochrome c reductase activity, suggesting that selenium does not significantly alter the metabolism of acetaminophen to reactive electrophilic metabolites by the cytochrome P-450-dependent mixed-function oxidase enzyme system. Selenium produced an increase in the activity of gamma-glutamylcysteine synthetase which may account for the increased glutathione availability in selenium-treated animals and increased the activities of glutathione S-transferase and glucose-6-phosphate dehydrogenase. Examination of the urinary metabolite profile in selenium-treated animals revealed that the urinary excretion of acetaminophen and its metabolites was significantly increased over a 72-hr period. The increase occurred in the AAP-glucuronide metabolite while parent AAP and AAP-sulfate were actually decreased in selenium-treated rats. No change in recovery was observed in the AAP-glutathione or AAP-mercapturate urinary metabolites. While the glutathione conjugating system is enhanced by selenium treatment, amelioration of acetaminophen toxicity is most likely the result of enhanced glucuronidation which effectively diverts the amount of acetaminophen to be converted by the cytochrome P-450 system to the toxic metabolite.
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PMID:Protective effects of selenium on acetaminophen-induced hepatotoxicity in the rat. 290 Nov 47


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