Determination of extracellular and intracellular enrichments of [1-13C]-α-ketoisovalerate using enzymatically converted [1-13C]-valine standardization curves and gas chromatography–mass spectrometry

Kulik, Wim; Jakobs, Cornelis; Meer, K. de

doi:10.1016/s0378-4347(99)00158-9

Cited by 13 publications

(3 citation statements)

References 14 publications

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“…A detailed description of KIV-measurement was previously described [ 14 ]. 13 C isotopic enrichment in the breath samples was analyzed by an infrared isotope analysis technique (Helifan, Analytic Fischer Instruments, Leipzig, Germany).…”

Section: Methodsmentioning

confidence: 99%

The effect of short-term high versus normal protein intake on whole-body protein synthesis and balance in children following cardiac surgery: a randomized double-blind controlled clinical trial

Geukers

Dijsselhof²,

Jansen

et al. 2015

Nutr J

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BackgroundInfants undergoing cardiac surgery are at risk of a negative protein balance, due to increased proteolysis in response to surgery and the cardiopulmonary bypass circuit, and limited intake. The aim of the study was to quantify the effect on protein kinetics of a short-term high-protein (HP) diet in infants following cardiac surgery.MethodsIn a prospective, double-blinded, randomized trial we compared the effects of a HP (5 g · kg−1 · d−1) versus normal protein (NP, 2 g · kg−1 · d−1) enteral diet on protein kinetics in children <24 months, on day 2 following surgical repair of congenital heart disease. Valine kinetics and fractional albumin synthesis rate (FSRalb) were measured with mass spectrometry using [1-13C]valine infusion. The Mann–Whitney U test was used to investigate differences between group medians. Additionally, the Hodges-Lehmann procedure was used to create a confidence interval with a point estimate of median differences between groups.ResultsTwenty-eight children (median age 9 months, median weight 7 kg) participated in the study, of whom in only 20 subjects isotopic data could be used for final calculations. Due to underpowering of our study, we could not draw conclusions on the primary outcome parameters. We observed valine synthesis rate of 2.73 (range: 0.94 to 3.36) and 2.26 (1.85 to 2.73) μmol · kg−1 · min−1 in the HP and NP diet, respectively. The net valine balance was 0.54 (−0.73 to 1.75) and 0.24 (−0.20 to 0.63) μmol · kg−1 · min−1 in the HP and NP group. Between groups, there was no difference in FSRalb. We observed increased oxidation and BUN in the HP diet, compared to the NP diet, as a plausible explanation of the metabolic fate of surplus protein.ConclusionsIt is plausible that the surplus protein in the HP group has caused the increase of valine oxidation and ureagenesis, compared to the NP group. Because too few patients had completed the study, we were unable to draw conclusions on the effect of a HP diet on protein synthesis and balance. We present our results as new hypothesis generating data.Trial registrationDutch Trial Register NTR2334.

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Section: Methodsmentioning

confidence: 99%

The effect of short-term high versus normal protein intake on whole-body protein synthesis and balance in children following cardiac surgery: a randomized double-blind controlled clinical trial

Geukers

Dijsselhof²,

Jansen

et al. 2015

Nutr J

View full text Add to dashboard Cite

show abstract

“…Samples were injected splitlessly onto a fused‐silica CP‐Sil‐19CB 25m × 0.25 mm (inner diameter) × 0.2 μm (film thickness) column (Chrompak International, Middelburg, The Netherlands) with helium as a carrier gas. Valine enrichment was determined by selected ion monitoring measurement of the N ‐methoxycarbonyl ester derivative at m/z 142.1 and 143.1 (20). Phenylalanine and tyrosine were converted to their methyl‐formated pentafluorobenzyl derivatives and monitored at m/z 190.2 and 195.2 for phenylalanine and 2 H 5 ‐phenylalanine, respectively, and at 264.2, 266.2 and 268.2 for tyrosine, 2 H 2 ‐tyrosine and 2 H 4 ‐tyrosine, respectively (21).…”

Section: Methodsmentioning

confidence: 99%

Whole Body Protein Turnover and Urea Production of Preterm Small for Gestational Age Infants Fed Fortified Human Milk or Preterm Formula

Boo

Cranendonk²,

Kulik³

et al. 2005

J. pediatr. gastroenterol. nutr.

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“…In blood samples (750 L) obtained between T ‫ס‬ 0 and 480 minutes, KIV was analyzed as the O-t-butyldimethylsilylquinoxalinol. 13 C enrichments were measured by gas chromatography mass spectrometry with positive chemical ionization (model 5989B, quadrupole GCMS system; Hewlett-Packard, Palo Alto, CA, U.S.A.) (8).…”

Section: Measurement Of 13 C-ketoisovalerate Enrichment In Plasmamentioning

confidence: 99%

A Single Food Bolus Stimulates Albumin Synthesis in Growing Piglets

de Meer,

Smolders,

Meesterburrie

et al. 2000

J. pediatr. gastroenterol. nutr.

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BackgroundA stable isotope tracer method to quantify the synthesis of proteins of hepatic origin in response to feeding is described. The response of albumin synthesis on one mixed meal in a piglet model was investigated and the intragastric and intravenous administration modes of 13C‐valine were compared.MethodsThe fasting and postprandial fractional synthesis rates (FSRs) of albumin in 15 piglets were measured while infusion rates of 13C‐valine were changed in anticipation of the increased appearance of the tracee after a single liquid food bolus (30 mL/kg infant formula). 13C‐valine enrichments in albumin hydrolysates at regular time intervals were determined with gas chromatography–combustion isotope ratio mass spectrometry.ResultsThe intravenous mode (n = 8) showed constant plasma α‐ketoisovalerate tracer‐to‐tracee ratios (coefficient of variation range: 1–8%), and a 27% increase in albumin FSR after the food bolus (mean FSR ± standard error [SE]: fasting 14.4% ± 1.6% vs. postprandial 18.3% ± 2.2% per day;P < 0.005). In the intragastric mode (n = 7), albumin FSR calculated from the mean precursor values increased 32% after feeding (fasting 14.6% ± 1.5% vs. postprandial 19.3% ± 1.6% per day;P = 0.005), despite absence of constant α‐ketoisovalerate enrichment (coefficient of variation range: 15–31%). The FSRs were not significantly different between both infusion modes.ConclusionsA mixed food bolus increases albumin FSR in growing piglets by approximately 30%, irrespective of the tracer administration route. The concept of anticipated precursor steady state is applicable to study changes of hepatic protein synthesis after a single meal. The intragastric mode of tracer administration can be applied as a less invasive method to measure tissue specific protein synthesis in children.

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Determination of extracellular and intracellular enrichments of [1-13C]-α-ketoisovalerate using enzymatically converted [1-13C]-valine standardization curves and gas chromatography–mass spectrometry

Cited by 13 publications

References 14 publications

The effect of short-term high versus normal protein intake on whole-body protein synthesis and balance in children following cardiac surgery: a randomized double-blind controlled clinical trial

The effect of short-term high versus normal protein intake on whole-body protein synthesis and balance in children following cardiac surgery: a randomized double-blind controlled clinical trial

Whole Body Protein Turnover and Urea Production of Preterm Small for Gestational Age Infants Fed Fortified Human Milk or Preterm Formula

A Single Food Bolus Stimulates Albumin Synthesis in Growing Piglets

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