Quantitation of 2-ketoacids in biological fluids by gas chromatography chemical ionization mass spectrometry ofO-trimethylsily-quinoxalinol derivatives

Rocchiccioli, F.; Leroux, Jean‐Paul; Cartier, P

doi:10.1002/bms.1200080406

Cited by 90 publications

(27 citation statements)

References 35 publications

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“…The concentrations of plasma Leu and a-ketoisocaproic acid (a-KIC) and enrichments of plasma [1-13 C]Leu and a-[1-13 C]KIC were determined by gas chromatography mass spectrometry (QP-2010, Shimadzu, Japan) by the procedures of Rocchiccioli et al (1981) and Calder and Smith (1988) as described previously (Sano et al 2004). The isotopic abundance of exhaled 13 CO 2 was determined with a gas chromatography-combustion-isotope ratio mass spectrometric system (DELTAplus, Thermo Electron, USA).…”

Section: Chemical Analysesmentioning

confidence: 99%

The effect of the source of nitrogen supplementation on nitrogen balance, rates of plasma leucine turnover, protein synthesis and degradation in sheep

Sano

Shibasaki

Sawada

2009

Archives of Animal Nutrition

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Combined experiments of the isotope dilution method of [1-(13)C]leucine, open-circuit calorimetry and nitrogen (N) balance test were used to determine the effect of the source of N supplementation on N balance, whole body protein synthesis (WBPS) and degradation (WBPD) in sheep. The experiment was performed in a replicated 3 × 3 Latin square design. The control diet consisted of timothy hay, ground maize and soybean meal. The urea diet was the control diet supplemented with 1.5% urea. The SBM diet contained the same N and metabolisable energy as the urea diet, which was reached by changing ground maize and soybean meal weights of the control diet. Nitrogen retention was greater (p < 0.05) for the urea diet than the control and SBM diets. Plasma urea concentrations were highest for the SBM diet, followed by the urea diet, and the control diet was lowest. The WBPS and WBPD did not differ between diets, but were numerically lower for the urea and SBM diets. These results suggest that in sheep, urea supplementation influenced N retention without clear changes in WBPS and WBPD.

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Section: Chemical Analysesmentioning

confidence: 99%

The effect of the source of nitrogen supplementation on nitrogen balance, rates of plasma leucine turnover, protein synthesis and degradation in sheep

Sano

Shibasaki

Sawada

2009

Archives of Animal Nutrition

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“…13 C]valine with the corresponding tracer mole ratio, as described earlier (33). Standards of [1-13 C]KIVA and patient plasma samples were processed in the same series.…”

Section: Experimental Designmentioning

confidence: 99%

Protein intake during hemodialysis maintains a positive whole body protein balance in chronic hemodialysis patients

Veeneman

Kingma²,

Boer³

et al. 2003

American Journal of Physiology-Endocrinology and Metabolism

109

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. Protein intake during hemodialysis maintains a positive whole body protein balance in chronic hemodialysis patients. Am J Physiol Endocrinol Metab 284: E954-E965, 2003. First published January 21, 2003 10.1152/ajpendo.00264.2002.-Protein energy malnutrition is present in 18 to 56% of hemodialysis patients. Because hemodialysis has been regarded as a catabolic event, we studied whether consumption of a protein-and energyenriched meal improves the whole body protein balance during dialysis in chronic hemodialysis (CHD) patients. Patients were studied on a single day between dialysis (HDϪ protocol) in the morning while fasting and in the afternoon while consuming six small test meals. Patients were also studied during two separate dialysis sessions (HDϩ protocol). Patients were fasted during one and consumed the meals during the other. Whole body protein metabolism was studied by primed constant infusion of L-[1-13 C]valine. During HDϪ, feeding changed the negative whole body protein balance observed during fasting to a positive protein balance. Dialysis deepened the negative balance during fasting, whereas feeding during dialysis induced a positive balance comparable to the HDϪ protocol while feeding. Plasma valine concentrations during the studies were correlated with whole body protein synthesis and inversely correlated with whole body protein breakdown. We conclude that the consumption of a protein-and energy-enriched meal by CHD patients while dialyzing can strongly improve whole body protein balance, probably because of the increased amino acid concentrations in blood. protein turnover; stable isotope; valine SIGNS OF PROTEIN ENERGY MALNUTRITION occur frequently in patients with chronic renal failure (17, 19). Protein energy malnutrition has been shown to be a major risk factor for increased morbidity and mortality in the chronic hemodialysis (CHD) patient (2, 17). Multiple factors predispose CHD patients to protein energy malnutrition, e.g., low caloric intake, low protein intake, and the hemodialysis procedure itself. Particularly, losses of amino acids or abnormal protein metabolism during hemodialysis might contribute to the observed protein energy malnutrition. Studies examining the role of CHD itself on protein metabolism are limited (22). Several lines of evidence indicate that the CHD procedure can result in a negative whole body protein balance. Nitrogen balance has been shown to be more negative on a dialysis day compared with a nondialysis day regardless of daily protein intake (5, 23). Lim et al. (22) studied whole body protein metabolism by applying the [ 13 C]leucine isotope dilution technique in fasting CHD patients during hemodialysis. They observed a reduction in whole body protein synthesis compared with the predialysis period, and this resulted in a doubling of the negative protein balance already present in fasting CHD patients. Furthermore, hemodialysis stimulates muscle protein losses compared with the predialysis period in fasting CHD patients (18).In apparently healthy subjects, the...

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“…Isotopic enrichments were determined by selected ion monitoring [M-57] ϩ at m/z 302 and 305 corresponding to natural leucine and [ 2 H 3 ]leucine, respectively. Measurement of the isotope enrichment of plasma ␣-KIC was performed using the extraction and quinoxalinol derivatization procedures of Rocchicchioli et al (29). The quinoxalinol-t-butyldimethysilyl derivative was then prepared according to the method of Langebeck et al (30) and analyzed by selected ion monitoring [M-57] ϩ at m/z 259 and 260, corresponding to ␣-KIC and [ 13 C] ␣-KIC, respectively.…”

Section: Analytical Methods (A) Infusate and Plasma Amino Acid Concenmentioning

confidence: 99%

Mechanisms permitting nephrotic patients to achieve nitrogen equilibrium with a protein-restricted diet.

Maroni

Staffeld²,

Young³

et al. 1997

J. Clin. Invest.

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Quantitation of 2-ketoacids in biological fluids by gas chromatography chemical ionization mass spectrometry ofO-trimethylsily-quinoxalinol derivatives

Cited by 90 publications

References 35 publications

The effect of the source of nitrogen supplementation on nitrogen balance, rates of plasma leucine turnover, protein synthesis and degradation in sheep

The effect of the source of nitrogen supplementation on nitrogen balance, rates of plasma leucine turnover, protein synthesis and degradation in sheep

Protein intake during hemodialysis maintains a positive whole body protein balance in chronic hemodialysis patients

Mechanisms permitting nephrotic patients to achieve nitrogen equilibrium with a protein-restricted diet.

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