INFLUENCE OF NANOSIZED SILICA OXIDE SUSPENSION ON NITRIC OXIDE PRODUCTION IN RATS TESTES DURING CHRONIC NITRATE-FLUORIDE INTOXICATION

In the Poltava region of Ukraine there is a high possibility of combined excessive intake of nitrates and fluorides, since the waters of the Buchaksʹkii aquifer are rich in fluorine ions, moreover, the Poltava region is a region with a developed agriculture. The purpose of this work is to determine the effect of nanosized silicon oxide suspension on the changes in the activity of nitric oxide cycle components, components, and, namely the total activity of NO-synthases (NOS), the activity of constitutive forms of NOS (cNOS), inducible form of NOS (iNOS), nitrate reductase, nitrite reductase, nitrite reductase, nitrite reductase in the testes of rats under the conditions of chronic combined nitrate-fluorodide intoxication. Materials and methods. The study was conducted on 15 mature male Wistar rats weighing 200-253 g. The animals were randomly divided into 3 groups of 5 animals in each. The first group received daily saline solution through a gastric tube. The second group (chronic combined intoxication group) received sodium nitrate and fluoride in a dosage of 500 mg / kg of sodium nitrate and 10 mg / kg of sodium fluoride. The third group against the background of chronic combined intoxication modelling additionally received a suspension of nanosized silicon oxide is a dosage of 100 mg / kg of active substance. Results. Chronic combined intoxication increases total NOS activity by 65.9% compared to the control group. The increase in NO production by NOS is the result of a 4-fold increase in iNOS activity, since the activity of cNOS under these conditions does not change significantly. Nitrite reductase-dependent NO production increases by 66.7%, nitrate reductase activity increases by 77.8%. Nitrite content in the testes homogenate grows in 2.17 times. Hydrolytic cleavage of L-arginine by arginase increases in 2.88 times. The introduction of nanosized silicon oxide suspension under the conditions of chronic combined intoxication did not statistically significantly change the total NOS activity and cNOS activity compared to the group exposed to chronic intoxication. However, iNOS activity reduces in 3.69 times. Nitrate reductase activity decreases in 1.6 times, while nitrite reductase activity decreases in 45%. The activity of arginases lowered in 2.38 times. The nitrite content of the testes cut down by 23.6%. Conclusions. Chronic combined nitrate-fluoride intoxication leads to the development of hyperproduction of nitric oxide in the testes of rats by activating the inducible isoform of NO synthase and nitrite reductases. The use of nanosized silica suspension during chronic combined intoxication is an effective method to correct nitric oxide overproduction in the testes of rats.

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Identification, Functional Studies, and Genomic Comparisons of New Members of the NnrR Regulon in Rhodobacter sphaeroides

Journal of Bacteriology ◽

10.1128/jb.01026-09 ◽

2009 ◽

Vol 192 (4) ◽

pp. 903-911 ◽

Cited By ~ 14

Author(s):

Angela Hartsock ◽

James P. Shapleigh

Keyword(s):

Nitric Oxide ◽

Rhodobacter Sphaeroides ◽

Nitrite Reductase ◽

Reductase Activity ◽

Nitrite Reduction ◽

No Production ◽

Nitric Oxide Reductase ◽

New Members ◽

Functional Studies ◽

The Status

ABSTRACT Analysis of the Rhodobacter sphaeroides 2.4.3 genome revealed four previously unidentified sequences similar to the binding site of the transcriptional regulator NnrR. Expression studies demonstrated that three of these sequences are within the promoters of genes, designated paz, norEF, and cdgA, in the NnrR regulon, while the status of the fourth sequence, within the tat operon promoter, remains uncertain. nnrV, under control of a previously identified NnrR site, was also identified. paz encodes a pseudoazurin that is a donor of electrons to nitrite reductase. paz inactivation did not decrease nitrite reductase activity, but loss of pseudoazurin and cytochrome c2 together reduced nitrite reduction. Inactivation of norEF reduced nitrite and nitric oxide reductase activity and increased the sensitivity to nitrite in a taxis assay. This suggests that loss of norEF increases NO production as a result of decreased nitric oxide reductase activity. 2.4.3 is the only strain of R. sphaeroides with norEF, even though all four of the strains whose genomes have been sequenced have the norCBQD operon and nnrR. norEF was shown to provide resistance to nitrite when it was mobilized into R. sphaeroides strain 2.4.1 containing nirK. Inactivation of the other identified genes did not reveal any detectable denitrification-related phenotype. The distribution of members of the NnrR regulon in R. sphaeroides revealed patterns of coselection of structural genes with the ancillary genes identified here. The strong coselection of these genes indicates their functional importance under real-world conditions, even though inactivation of the majority of them does not impact denitrification under laboratory conditions.

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La dénitrification chez Bacillus licheniformis

Canadian Journal of Microbiology ◽

10.1139/m78-008 ◽

1978 ◽

Vol 24 (1) ◽

pp. 45-49 ◽

Cited By ~ 12

Author(s):

F. Pichinoty ◽

J.-L. Garcia ◽

C. Job ◽

M. Durand

Keyword(s):

Nitric Oxide ◽

Gas Chromatography ◽

Nitrate Reductase ◽

Electron Donor ◽

Bacillus Licheniformis ◽

Nitrite Reductase ◽

Reductase Activity ◽

Cell Extracts ◽

Nitrite Reductase Activity ◽

Peptone Medium

The denitrifying capacity of 15 strains of Bacillus licheniformis was evaluated. In general, N2 production by the cultures on complex media containing NO3− is irregular and quite slow and three of the strains never produce gas. Bacillus licheniformis grows rapidly in anaerobiosis on peptone medium containing NO3− which is reduced to NO2−. None of the strains grow in peptone medium with NO2− or N2O as the respiratory substrate, nor do they grow under an atmosphere of 10% NO–90% N2. Denitrification was studied in cell suspensions using gas chromatography. N2O production from NO3− or NO2− is always weak at best; nitric oxide is reduced to N2O at an appreciable rate. All the strains synthesize nitrate reductase A in anaerobiosis when NO3− is present. In cell extracts, nitrite reductase activity is always negligible or nil with tetramethyl-p-phenylenediamine as an electron donor.

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Effects of chitosan on nitric oxide production and inducible nitric oxide synthase activity and mRNA expression in weaned piglets

Czech Journal of Animal Science ◽

10.17221/8405-cjas ◽

2018 ◽

Vol 60 (No. 8) ◽

pp. 359-366

Author(s):

J. Li ◽

B. Shi ◽

S. Yan ◽

L. Jin ◽

Y. Guo ◽

...

Keyword(s):

Nitric Oxide ◽

Mrna Expression ◽

Inducible Nitric Oxide Synthase ◽

No Production ◽

Weaned Piglets ◽

Inos Activity ◽

Oxide Synthase ◽

Inducible Nitric Oxide

The effects of chitosan on nitric oxide (NO) production and inducible nitric oxide synthase (iNOS) activity and gene expression in vivo or vitro were investigated in weaned piglets. In vivo, 180 weaned piglets were assigned to five dietary treatments with six replicates. The piglets were fed on a basal diet supplemented with 0 (control), 100, 500, 1000, and 2000 mg chitosan/kg feed, respectively. In vitro, the peripheral blood mononuclear cells (PBMCs) from a weaned piglet were cultured respectively with 0 (control), 40, 80, 160, and 320 µg chitosan/ml medium. Results showed that serum NO concentrations on days 14 and 28 and iNOS activity on day 28 were quadratically improved with increasing chitosan dose (P < 0.05). The iNOS mRNA expressions were linearly or quadratically enhanced in the duodenum on day 28, and were improved quadratically in the jejunum on days 14 and 28 and in the ileum on day 28 (P < 0.01). In vitro, the NO concentrations, iNOS activity, and mRNA expression in unstimulated PBMCs were quadratically enhanced by chitosan, but the improvement of NO concentrations and iNOS activity by chitosan were markedly inhibited by N-(3-[aminomethyl] benzyl) acetamidine (1400w) (P < 0.05). Moreover, the increase of NO concentrations, iNOS activity, and mRNA expression in PBMCs induced by lipopolysaccharide (LPS) were suppressed significantly by chitosan (P < 0.05). The results indicated that the NO concentrations, iNOS activity, and mRNA expression in piglets were increased by feeding chitosan in a dose-dependent manner. In addition, chitosan improved the NO production in unstimulated PBMCs but inhibited its production in LPS-induced cells, which exerted bidirectional regulatory effects on the NO production via modulated iNOS activity and mRNA expression.

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Increased nitrite reductase activity of fetal versus adult ovine hemoglobin

AJP Heart and Circulatory Physiology ◽

10.1152/ajpheart.00601.2008 ◽

2009 ◽

Vol 296 (2) ◽

pp. H237-H246 ◽

Cited By ~ 21

Author(s):

Arlin B. Blood ◽

Mauro Tiso ◽

Shilpa T. Verma ◽

Jennifer Lo ◽

Mahesh S. Joshi ◽

...

Keyword(s):

Nitrite Reductase ◽

Chronic Hypoxia ◽

Reductase Activity ◽

Fetal Hemoglobin ◽

Nitrite Reduction ◽

No Production ◽

Low Oxygen ◽

Nitrite Reductase Activity ◽

Adult Hemoglobin ◽

Severe Ischemia

Growing evidence indicates that nitrite, NO2−, serves as a circulating reservoir of nitric oxide (NO) bioactivity that is activated during physiological and pathological hypoxia. One of the intravascular mechanisms for nitrite conversion to NO is a chemical nitrite reductase activity of deoxyhemoglobin. The rate of NO production from this reaction is increased when hemoglobin is in the R conformation. Because the mammalian fetus exists in a low-oxygen environment compared with the adult and is exposed to episodes of severe ischemia during the normal birthing process, and because fetal hemoglobin assumes the R conformation more readily than adult hemoglobin, we hypothesized that nitrite reduction to NO may be enhanced in the fetal circulation. We found that the reaction was faster for fetal than maternal hemoglobin or blood and that the reactions were fastest at 50–80% oxygen saturation, consistent with an R-state catalysis that is predominant for fetal hemoglobin. Nitrite concentrations were similar in blood taken from chronically instrumented normoxic ewes and their fetuses but were elevated in response to chronic hypoxia. The findings suggest an augmented nitrite reductase activity of fetal hemoglobin and that the production of nitrite may participate in the regulation of vascular NO homeostasis in the fetus.

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Nitrate Reductase and Nitrite Reductase Activity in Dark-Grown Radish Seedlings: Relation to the Supply of NADPH

Physiologia Plantarum ◽

10.1111/j.1399-3054.1976.tb03947.x ◽

1976 ◽

Vol 37 (2) ◽

pp. 139-142 ◽

Cited By ~ 10

Author(s):

INEKE STULEN ◽

L. LANTING

Keyword(s):

Nitrate Reductase ◽

Nitrite Reductase ◽

Reductase Activity ◽

Nitrite Reductase Activity ◽

Radish Seedlings

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Nitric Oxide Production Mediated by Nitrate Reductase in the Green Alga Chlamydomonas reinhardtii: an Alternative NO Production Pathway in Photosynthetic Organisms

Plant and Cell Physiology ◽

10.1093/pcp/pcf034 ◽

2002 ◽

Vol 43 (3) ◽

pp. 290-297 ◽

Cited By ~ 158

Author(s):

Yasuko Sakihama ◽

Soichi Nakamura ◽

Hideo Yamasaki

Keyword(s):

Nitric Oxide ◽

Nitrate Reductase ◽

Chlamydomonas Reinhardtii ◽

Green Alga ◽

No Production ◽

Nitric Oxide Production ◽

Photosynthetic Organisms ◽

Oxide Production

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Production and consumption of nitric oxide by denitrifyingFlexibacter canadensis

Canadian Journal of Microbiology ◽

10.1139/m95-078 ◽

1995 ◽

Vol 41 (7) ◽

pp. 585-591 ◽

Cited By ~ 6

Author(s):

Qitu Wu ◽

Roger Knowles ◽

Yiu-Kwok Chan

Keyword(s):

Nitric Oxide ◽

Nitrite Reductase ◽

Chelating Agent ◽

No Production ◽

Production And Consumption ◽

Carbonyl Cyanide ◽

No Consumption ◽

High Concentrations ◽

Ph Range ◽

Triton X

Production and consumption of nitric oxide (NO) by Flexibacter canadensis cells under anaerobic conditions was investigated using a chemiluminescence NO analyzer. Net NO production from nitrite in the presence of carbonyl cyanide m-chlorophenylhydrazone (CCCP) was pH dependent, increased in the pH range from 4.5 to 6.5, and sharply decreased at pH >6.5. CCCP inhibited NO consumption but only at pH values ≤6.5. This can explain why CCCP stimulation of NO production depends on the pH. Denitrification of nitrite at high concentrations (≥5 mM) also resulted in net NO accumulation. Diethyldithiocarbamate, a copper chelating agent, prevented not only net production of NO during the reduction of nitrite in the presence of CCCP, but also production of nitrous oxide (N2O) from nitrite in the presence of C2H2. This suggests that F. canadensis may possess a copper-type nitrite reductase. However, cytochrome cd1- and copper-containing nitrite reductase DNA probes from Pseudomonas species did not hybridize with the total DNA of F. canadensis, indicating that the nitrite reductase of F. canadensis may possess unique properties. In addition to diethyldithiocarbamate, sulfide, carbon monoxide, azide, cyanide, hydroxylamine and Triton X-100 prevented net NO production from nitrite in the presence of CCCP, and also inhibited NO consumption. C2H2, an inhibitor of N2O reductase, did not affect NO production or consumption.Key words: nitrite reductase, nitric oxide (NO), carbonyl cyanide m-chlorophenylhydrazone (CCCP), Flexibacter canadensis.

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Effects of oxygen on each step of denitrification on Pseudomonas nautica

Canadian Journal of Microbiology ◽

10.1139/m89-177 ◽

1989 ◽

Vol 35 (11) ◽

pp. 1061-1064 ◽

Cited By ~ 90

Author(s):

P. Bonin ◽

M. Gilewicz ◽

J. C. Bertrand

Keyword(s):

Nitrous Oxide ◽

Nitrate Reductase ◽

Oxygen Concentration ◽

Nitrite Reductase ◽

Nitrate Reductase Activity ◽

Reductase Activity ◽

A Value ◽

Nitrite Reductase Activity ◽

Effect Of Oxygen

Studies on the effect of oxygen on denitrification have shown that denitrification on Pseudomonas nautica 617 can take place in the presence of oxygen. The enzymes associated with denitrification are affected differently with respect to oxygen concentration. Nitrate reductase was less sensitive toward oxygen than nitrite and nitrous oxide reductases. Nitrate reductase activity was completely blocked at an oxygen concentration greater than 4.05 mg/L, compared with 2.15 and 0.25 mg/L for nitrite and nitrous oxide reductases, respectively. After an aerobic–anaerobic shift, nitrate reductase activity remained unchanged whereas the rate of nitrite reductase activity rose to a value only 20% that of the original rate.Key words: denitrification, oxygen, Pseudomonas.

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