scholarly journals The effect of dietary nitrate on nitrate and nitrite excretion in man

1990 ◽  
Vol 64 (2) ◽  
pp. 387-397 ◽  
Author(s):  
T. H. J. Florin ◽  
G. Neale ◽  
J. H. Cummings
Keyword(s):  
Normal Subjects ◽  
Anion Exchange Chromatography ◽  
Exchange Chromatography ◽  
Nitroso Compounds ◽  
Nitrate Content ◽  
Sodium Absorption ◽  
Dietary Intakes ◽  
Dietary Nitrate ◽  
Nitrate Losses ◽  
Nitrate And Nitrite

Dietary nitrate and nitrite may affect colonic pathophysiology. These anions influence fermentation, and nitrite has been shown to augment sodium absorption by the colon and participate in the formation ofN-nitroso compounds. There is, however, no general agreement as to how much dietary nitrate and nitrite reaches the colon. To help resolve this question, balance studies were performed on six healthy ileostomy subjects who were given diets that varied in nitrate content from 0.83 to 5.20 mmol/d. Nitrate and nitrite excretion in ileal effluent and urine were measured by anion-exchange chromatography with conductivity detection. There was no significant nitrite in the diets, urine, or ideal effluent. Dietary nitrate was largely excreted in urine (1.31–4.25 mmol/d). The urinary excretion findings indicated net synthesis of nitrate at low dietary intakes and net catabolism of nitrate at high intakes. Nitrate losses in ileal effluent were very low (0.03–0.05 mmol/d, 0.03–0.06 mmol/kg) and unrelated to intake for all the diets. It is concluded that dietary nitrate and nitrite do not enter the colon from the small intestine in amounts that would affect fermentation and mucosal metabolism in man. The possibility of significant amounts of nitrate reaching the colon via blood in normal subjects has not been excluded.

Radioimmunoassay for pancreatic polypeptide, and its age-related changes in concentration.

1983 ◽  
Vol 29 (11) ◽  
pp. 1923-1927 ◽  
Author(s):  
M M O'Hare ◽  
J G Daly ◽  
K D Buchanan
Keyword(s):  
Pancreatic Polypeptide ◽  
Medullary Carcinoma ◽  
Normal Subjects ◽  
Reference Interval ◽  
Anion Exchange Chromatography ◽  
Endocrine Tumor ◽  
Exchange Chromatography ◽  
Skewed Distribution ◽  
Endocrine Tumors ◽  
Age Related

Abstract Pancreatic polypeptide (PP), a recently discovered pancreatic hormone, is potentially a marker for endocrine tumors. Consequently, we devised a radioimmunoassay for it, using antisera (raised in rabbits) to bovine PP, 125I-labeled bovine PP (purified by anion-exchange chromatography), and human PP standards. Concentrations circulating in fasting, normal subjects were measured. Statistical analysis of the results revealed a skewed distribution. An age-related increase was also observed. Evaluating PP concentrations in sera from 23 patients with endocrine tumors, we found increased values in a few cases of Zollinger-Ellison syndrome, medullary carcinoma of the thyroid, carcinoid syndrome, and one tumor producing vasoactive intestinal polypeptide (VIPoma). In contrast, values from five insulinomas and one glucagonoma were within the normal reference interval. Thus, an increased value for PP in a fasting individual may suggest the diagnosis of an endocrine tumor but is not a diagnostic prerequisite.

A composite biochemical system for bacterial nitrate and nitrite assimilation as exemplified by Paracoccus denitrificans

2011 ◽  
Vol 435 (3) ◽  
pp. 743-753 ◽  
Author(s):  
Andrew J. Gates ◽  
Victor M. Luque-Almagro ◽  
Alan D. Goddard ◽  
Stuart J. Ferguson ◽  
M. Dolores Roldán ◽  
...  
Keyword(s):  
Nitrate Reductase ◽  
Nitrogen Source ◽  
Nitrite Reductase ◽  
Paracoccus Denitrificans ◽  
Gene Clusters ◽  
Anion Exchange Chromatography ◽  
Exchange Chromatography ◽  
Nitrite Reduction ◽  
Anaerobic Growth ◽  
Nitrate And Nitrite

The denitrifying bacterium Paracoccus denitrificans can grow aerobically or anaerobically using nitrate or nitrite as the sole nitrogen source. The biochemical pathway responsible is expressed from a gene cluster comprising a nitrate/nitrite transporter (NasA), nitrite transporter (NasH), nitrite reductase (NasB), ferredoxin (NasG) and nitrate reductase (NasC). NasB and NasG are essential for growth with nitrate or nitrite as the nitrogen source. NADH serves as the electron donor for nitrate and nitrite reduction, but only NasB has a NADH-oxidizing domain. Nitrate and nitrite reductase activities show the same Km for NADH and can be separated by anion-exchange chromatography, but only fractions containing NasB retain the ability to oxidize NADH. This implies that NasG mediates electron flux from the NADH-oxidizing site in NasB to the sites of nitrate and nitrite reduction in NasC and NasB respectively. Delivery of extracellular nitrate to NasBGC is mediated by NasA, but both NasA and NasH contribute to nitrite uptake. The roles of NasA and NasC can be substituted during anaerobic growth by the biochemically distinct membrane-bound respiratory nitrate reductase (Nar), demonstrating functional overlap. nasG is highly conserved in nitrate/nitrite assimilation gene clusters, which is consistent with a key role for the NasG ferredoxin, as part of a phylogenetically widespread composite nitrate and nitrite reductase system.

scholarly journals Sodium nitrate ingestion increases skeletal muscle nitrate content in humans

2017 ◽  
Vol 123 (3) ◽  
pp. 637-644 ◽  
Author(s):  
Jean Nyakayiru ◽  
Imre W. K. Kouw ◽  
Naomi M. Cermak ◽  
Joan M. Senden ◽  
Luc J. C. van Loon ◽  
...  
Keyword(s):  
Skeletal Muscle ◽  
Muscle Tissue ◽  
Sodium Nitrate ◽  
Human Skeletal Muscle ◽  
Skeletal Muscle Tissue ◽  
Nitrate Content ◽  
No Production ◽  
Dietary Nitrate ◽  
Plasma Nitrite ◽  
Nitrate And Nitrite

Nitrate ([Formula: see text]) ingestion has been shown to have vasoactive and ergogenic effects that have been attributed to increased nitric oxide (NO) production. Recent observations in rodents suggest that skeletal muscle tissue serves as an endogenous [Formula: see text] “reservoir.” The present study determined [Formula: see text] contents in human skeletal muscle tissue in a postabsorptive state and following ingestion of a sodium nitrate bolus (NaNO3). Seventeen male, type 2 diabetes patients (age 72 ± 1 yr; body mass index 26.5 ± 0.5 kg/m2; means ± SE) were randomized to ingest a dose of NaNO3 (NIT; 9.3 mg [Formula: see text]/kg body wt) or placebo (PLA; 8.8 mg NaCl/kg body wt). Blood and muscle biopsy samples were taken before and up to 7 h following [Formula: see text] or placebo ingestion to assess [Formula: see text] [and plasma nitrite ([Formula: see text])] concentrations. Additionally, basal plasma and muscle [Formula: see text] concentrations were assessed in 10 healthy young (CON-Y; age 21 ± 1 yr) and 10 healthy older (CON-O; age 75 ± 1 yr) control subjects. In all groups, baseline [Formula: see text] concentrations were higher in muscle (NIT, 57 ± 7; PLA, 61 ± 7; CON-Y, 80 ± 10; CON-O, 54 ± 6 µmol/l) than in plasma (NIT, 35 ± 3; PLA, 32 ± 3; CON-Y, 38 ± 3; CON-O, 33 ± 3 µmol/l; P ≤ 0.011). Ingestion of NaNO3 resulted in a sustained increase in plasma [Formula: see text], plasma [Formula: see text], and muscle [Formula: see text] concentrations (up to 185 ± 25 µmol/l) in the NIT group (time effect P < 0.001) compared with PLA (treatment effect P < 0.05). In conclusion, basal [Formula: see text] concentrations are substantially higher in human skeletal muscle tissue compared with plasma. Ingestion of a bolus of dietary [Formula: see text] increases both plasma and muscle [Formula: see text] contents in humans. NEW & NOTEWORTHY Literature of the pharmacokinetics following dietary nitrate ingestion is usually limited to the changes observed in plasma nitrate and nitrite concentrations. The present investigation assessed the skeletal muscle nitrate content in humans during the postabsorptive state, as well as following dietary nitrate ingestion. We show that basal nitrate content is higher in skeletal muscle tissue than in plasma and that ingestion of a dietary nitrate bolus strongly increases both plasma and muscle nitrate concentrations.

The Characteristics of Ferritin from Human Tissues, Serum and Blood Cells

1975 ◽  
Vol 48 (5) ◽  
pp. 441-451 ◽  
Author(s):  
M. Worwood ◽  
W. Aherne ◽  
S. Dawkins ◽  
A. Jacobs
Keyword(s):  
Iron Overload ◽  
Anion Exchange ◽  
Serum Ferritin ◽  
Blood Cells ◽  
Density Gradient Centrifugation ◽  
Gradient Centrifugation ◽  
Normal Subjects ◽  
Anion Exchange Chromatography ◽  
Exchange Chromatography ◽  
Anion Exchange Column

1. The properties of ferritin in serum have been compared with those of ferritin from a number of tissues including blood cells. On anion-exchange chromatography with DEAE-Sephadex, the behaviour of human heart ferritin is different from that of liver, kidney or spleen ferritin. Reticulocyte ferritin appears to have similar characteristics to heart ferritin. 2. Serum ferritin from normal subjects and patients with various degrees of iron load, leukaemia or liver disease all have a much lower affinity for the anion-exchange column than any tissue ferritin, suggesting a difference in isoelectric point. The elution point of serum ferritin from patients with acute myeloblastic leukaemia is significantly different from normal. 3. Density gradient centrifugation in sucrose showed that ferritin in leucocyte extracts and partially purified ferritin from the serum of two patients with iron overload behaved as apoferritin rather than the iron-rich protein. 4. The results suggest that ferritin is modified during its entry into the plasma and that even in cases of iron overload the iron content of serum ferritin may be low. The findings are of importance in considering the origin of plasma ferritin, the clearance of ferritin from plasma and its role in iron metabolism.

scholarly journals Development and calibration of a dietary nitrate and nitrite database in the NIH–AARP Diet and Health Study

2015 ◽  
Vol 19 (11) ◽  
pp. 1934-1943 ◽  
Author(s):  
Maki Inoue-Choi ◽  
Mandeep K Virk-Baker ◽  
Briseis Aschebrook-Kilfoy ◽  
Amanda J Cross ◽  
Amy F Subar ◽  
...  
Keyword(s):  
Reference Data ◽  
Correlation Coefficients ◽  
National Institutes Of Health ◽  
Nitroso Compounds ◽  
Health Study ◽  
Food Category ◽  
Men And Women ◽  
Dietary Nitrate ◽  
Calibration Study ◽  
Nitrate And Nitrite

AbstractObjectiveNitrate and nitrite are probable human carcinogens when ingested under conditions that increase the formation of N-nitroso compounds. There have been limited efforts to develop US databases of dietary nitrate and nitrite for standard FFQ. Here we describe the development of a dietary nitrate and nitrite database and its calibration.DesignWe analysed data from a calibration study of 1942 members of the NIH–AARP (NIH–AARP, National Institutes of Health–AARP) Diet and Health Study who reported all foods and beverages consumed on the preceding day in two non-consecutive 24 h dietary recalls (24HR) and completed an FFQ. Based on a literature review, we developed a database of nitrate and nitrite contents for foods reported on these 24HR and for food category line items on the FFQ. We calculated daily nitrate and nitrite intakes for both instruments, and used a measurement error model to compute correlation coefficients and attenuation factors for the FFQ-based intake estimates using 24HR-based values as reference data.ResultsFFQ-based median nitrate intake was 68·9 and 74·1 mg/d, and nitrite intake was 1·3 and 1·0 mg/d, in men and women, respectively. These values were similar to 24HR-based intake estimates. Energy-adjusted correlation coefficients between FFQ- and 24HR-based values for men and women respectively were 0·59 and 0·57 for nitrate and 0·59 and 0·58 for nitrite; energy-adjusted attenuation factors were 0·59 and 0·57 for nitrate and 0·47 and 0·38 for nitrite.ConclusionsThe performance of the FFQ in assessing dietary nitrate and nitrite intakes is comparable to that for many other macro- and micronutrients.

Extracellular polysaccharides from suspension cultures of Nicotiana plumbaginifolia

2020 ◽  
Author(s):  
Ian Sims ◽  
A Bacic
Keyword(s):  
Uronic Acid ◽  
Cell Suspension Cultures ◽  
Anion Exchange Chromatography ◽  
Nicotiana Plumbaginifolia ◽  
Suspension Cultures ◽  
Exchange Chromatography ◽  
Arabinogalactan Protein ◽  
Extracellular Polysaccharides ◽  
Selective Precipitation ◽  
The Individual

The soluble polymers secreted by cell-suspension cultures of Nicotiana plumbaginifolia contained 78% carbohydrate, 6% protein and 4% inorganic material. The extracellular polysaccharides were separated into three fractions by anion-exchange chromatography using a gradient of imidazole-HCl at pH 7 and the individual polysaccharides in each fraction were then isolated by selective precipitation and enzymic treatment. Monosaccharide and linkage compositions were determined for each polysaccharide after reduction of uronic acid residues and the degree of esterification of the various uronic acid residues in each polysaccharide was determined concurrently with the linkage types. Six components were identified: an arabinoxyloglucan (comprising 34% of the total polysaccharide) and a galactoglucomannan (15%) in the unbound neutral fraction, a type II arabinogalactan (an arabinogalactan-protein, 11%) and an acidic xylan (3%) in the first bound fraction, and an arabinoglucuronomannan (11%) and a galacturonan (26%) in the second bound fraction. © 1995.

Nitrite and Nitrate Levels in Groundwater, Water Distribution Network, Bottled Water and Juices in Iran : A systematic Review

2020 ◽  
Vol 21 ◽  
Author(s):  
Maasoumeh Marhamati ◽  
Asma Afshari ◽  
Behzad Kiani ◽  
Behrooz Jannat ◽  
Mohammad Hashemi
Keyword(s):  
Drinking Water ◽  
Water Distribution ◽  
Scientific Information ◽  
Distribution Network ◽  
Water Distribution Network ◽  
The Body ◽  
International Standards ◽  
Nitrogen Fertilizers ◽  
Nitrate Content ◽  
Nitrate And Nitrite

Background: Nitrate and nitrite can get into the body through the consumption of contaminated water either directly or indirectly. The accumulation of these compounds in the body, in the long run, leads to health problems, for example, digestive disorders, cancers, and even death threats in children. The aim of this review is to investigate nitrate and nitrite pollution levels in drinking water and fruit juices in Iran. Methods: In this review data were collected through searching the Scientific Information Database, Science-Direct, Scopus, PubMed, Google Scholar, and Magiran databases using the keywords Nitrate, Nitrite, Drinking water, Drinking Water Resources, Juice and Iran. Finally, the location of the studies was geocoded through the Google My Maps (https://www.google.com/mymaps) software. Results: Studies clearly indicated that the juices are safe in terms of nitrate. Nitrate and nitrite values were less than the national and international standards in all samples of bottled drinking water except for a few of the studies. The results of the reviewed studies also indicated that the nitrate content was higher than that written on the label in 96% of the samples, and nitrite was not labeled in 80% of them. The nitrate quantity was higher than the permissible limit, in the water distribution network of Bushehr, Gilan and Mazandaran Provinces. Talesh, Ardabil, Hashtgerd, Divandareh, and Kerman cities had high nitrate levels in more than 50% of wells. Conclusion: Using nitrogen fertilizers and lack of a wastewater treatment system were the main reasons for the presence of nitrate and nitrite.

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