15N-labelled nitrite/nitrate tracer analysis by LC-MS/MS: Urinary and fecal excretion of nitrite/nitrate following oral administration to mice

Hu, Chiung‐Wen; Chang, Yuan-Jhe; Yen, Chi-Hua; Chen, Jian‐Lian; Muthukumaran, Rajendra Bose; Chao, Mu‐Rong

doi:10.1016/j.freeradbiomed.2019.08.005

Cited by 9 publications

(11 citation statements)

References 30 publications

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“…It may also harbor a shunt to generate nitric oxide (NO·) and citrulline from arginine [ 122 ]. The daily losses of N via the NO· pathway are a fraction of the overall N excretion, essentially made up from nitrogen oxides released through respiration [ 123 ] (a few µg/day) or further oxidized to nitrite, nitrate, and other nitroxylated compounds [ 124 , 125 ], which are excreted via saliva, urine, and stool [ 126 , 127 ]. However, there is proof of an additional, quantitatively significant, excretion of N as gas through respiration [ 128 , 129 ] that is supplementary to the standard and well-controlled urea excretion.…”

Section: The Dangerous Duality Of Needed 2-amino-nitrogen Preservamentioning

confidence: 99%

Dietary Energy Partition: The Central Role of Glucose

Remesar

Alemany

2020

IJMS

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Humans have developed effective survival mechanisms under conditions of nutrient (and energy) scarcity. Nevertheless, today, most humans face a quite different situation: excess of nutrients, especially those high in amino-nitrogen and energy (largely fat). The lack of mechanisms to prevent energy overload and the effective persistence of the mechanisms hoarding key nutrients such as amino acids has resulted in deep disorders of substrate handling. There is too often a massive untreatable accumulation of body fat in the presence of severe metabolic disorders of energy utilization and disposal, which become chronic and go much beyond the most obvious problems: diabetes, circulatory, renal and nervous disorders included loosely within the metabolic syndrome. We lack basic knowledge on diet nutrient dynamics at the tissue-cell metabolism level, and this adds to widely used medical procedures lacking sufficient scientific support, with limited or nil success. In the present longitudinal analysis of the fate of dietary nutrients, we have focused on glucose as an example of a largely unknown entity. Even most studies on hyper-energetic diets or their later consequences tend to ignore the critical role of carbohydrate (and nitrogen disposal) as (probably) the two main factors affecting the substrate partition and metabolism.

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Section: The Dangerous Duality Of Needed 2-amino-nitrogen Preservamentioning

confidence: 99%

Dietary Energy Partition: The Central Role of Glucose

Remesar

Alemany

2020

IJMS

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“…Second, the inflammation-associated markers (e.g., C-reactive protein, 3-nitrotyrosine and 8-nitroguanine) could be included to further investigate the putative implication of microbial infection-induced inflammation. Third, the elevated nitrite concentrations and nitrite/nitrate ratios associated with infection could be further substantiated by spiking the 15 N-labeled nitrate into the IPEs and tracing the microbial transformation of 15 N-labeled nitrate to 15 N-labeled nitrite using a 15 N-labeled nitrite/nitrate tracer analysis by LC-MS/MS [ 15 ]. Finally, since nitrate is the denominator term in calculating the nitrite/nitrate ratio, a high dietary intake of nitrate might reduce the ratio and requires further investigation.…”

Section: Discussionmentioning

confidence: 99%

“…Because the lifespan of NO is extremely short in humans, its major metabolites, nitrite and nitrate, have attracted significant attention in recent decades [ 12 ]. Since previous studies have shown that nitrite rather than nitrate reflects the regional endothelial iNOS activity during inflammation [ 13 ], and nitrite is less influenced by diet than nitrate [ 14 , 15 ], the nitrite level alone or the ratio of nitrite/nitrate in biological samples has been evaluated for its potential in clinical diagnosis. Elevated levels of nitrite in sputum were observed in patients with chronic obstructive pulmonary disease [ 16 ] or in the breath condensates of children with respiratory disease [ 17 ].…”

Section: Introductionmentioning

confidence: 99%

Elevated Nitrite/Nitrate Ratio as a Potential Biomarker for the Differential Diagnosis of Pleural Effusions

et al. 2022

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Pleural effusions (PEs) are common in clinical practice and can be due to many different underlying diseases such as cancer, congestive heart failure, or pneumonia. An accurate differential diagnostic categorization is essential, as the treatment and prognosis of PEs largely depend on its cause. In this study, we tested the hypothesis that nitrite and nitrate concentrations in PEs are associated with the inflammation and infection conditions. We therefore measured the nitrite and nitrate levels in 143 PE samples using a sensitive liquid chromatography-tandem mass spectrometry method and investigated their diagnostic potential in differentiating PEs. The results showed that nitrite concentrations and nitrite/nitrate ratios were higher in exudates than in transudates (NO2−: 2.12 vs. 1.49 μM; NO2−/NO3−: 23.3 vs. 14.0). Both the nitrite concentrations and the nitrite/nitrate ratios were positively correlated with the three Light’s criteria. Moreover, the receiver operating characteristic curve analysis revealed that the nitrite/nitrate ratio with an area under the curve of 0.71 could be a potential diagnostic biomarker in separating infectious PEs (IPEs) from other types of PEs. Taken together, the nitrite/nitrate ratio not only reflected the statuses of inflammation, but also the nitrate reduction by pathogenic bacteria infection in the pleural cavity. The nitrite/nitrate ratio could be a better biomarker in the differential diagnosis of PEs than the nitrite concentration alone.

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“…A major part of ingested nitrate is excreted in the urine within 48 hours. 4 Since NO is crucially involved in the regulation of cardiovascular and metabolic functions great attention has been paid to the possibility of boosting NO generation by the dietary administration of inorganic nitrate or nitrite. Numerous experimental studies, using cardiovascular and metabolic disease models, have demonstrated beneficial effects of nitrate and nitrite treatment, including blood pressure reduction and improved glucose control.…”

Section: Introductionmentioning

confidence: 99%

“…The kidneys play an important role in the regulation of nitrate and nitrite, although the details regarding the tubular handling of these anions are not yet clear. A major part of ingested nitrate is excreted in the urine within 48 hours 4 …”

Section: Introductionmentioning

confidence: 99%