Evaluation of Taurine Metabolism in Cats by Dual Stable Isotope Analysis

Fay, Laurent B.; Métairon, Sylviane; Montigon, Franck; Ballèvre, Olivier

doi:10.1006/abio.1998.2672

Cited by 6 publications

(2 citation statements)

References 21 publications

(18 reference statements)

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“…For the TTR calculation, the first approach applied was based on the Rosenblatt approach 11 which was also used in several tracer studies for 13 C short-chain fatty acids 30 or for 15 N-and 13 C-labelled taurine. 23 With this classical method, multiple correction factors are used in the calculation and these may represent a source of error. To reduce this, we also investigated the matrix approach to obtain the true mass isotopomer distribution.…”

Section: N-isotopic Enrichmentsmentioning

confidence: 99%

Simultaneous measurement of ¹³C‐ and ¹⁵N‐isotopic enrichments of threonine by mass spectrometry

Godin

Mermoud

Rémond

et al. 2009

Rapid Comm Mass Spectrometry

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Under conditions of high isotopic dilution, e.g. in a tracer study, the ability to determine accurately and quantitatively small variations in isotopic enrichments of differently labelled chemical compounds (e.g. (13)C and (15)N in threonine) in a single run by gas chromatography/mass spectrometry (GC/MS) is desirable but remains a technological challenge. Here, we report a new, rapid and simple GC/MS method for simultaneously measuring the isotopic enrichments of doubly labelled threonine ([U(13)C] and (15)N) with isotopic enrichment lower than 1.5 Molar Percent Excess (MPE). The long-term reproducibility measured was around 0.09 MPE for both tracers (throughout a 6 week period). The intra-day repeatability was lower than 0.05 and 0.06 MPE for [U(13)C]-Thr and (15)N-Thr, respectively. To calculate both isotopic enrichments, two modes of calculations were used: one based on work by Rosenblatt et al. in 1992 and the other one using a matrix approach. Both methods gave similar results (ANOVA, P >0.05) with close precision for each mode of calculation. The GC/MS method was then used to investigate the differential utilization of threonine in different organs according to its route of administration in minipigs after administration of both tracers. In plasma samples, the lowest isotopic enrichment measured between two successive time points was at 0.01 and 0.02 MPE for [U(13)C]-Thr and (15)N-Thr, respectively. Moreover, the accuracy of GC/MS (13)C-isotopic enrichment measured was validated by analyzing the same plasma samples by gas chromatography/combustion/isotope ratio mass spectrometry (GC/C/IRMS). Statistical analysis showed that both techniques gave the same results (ANOVA, P >0.05). This new GC/MS method offers the possibility to measure (13)C- and (15)N-isotopic enrichments with higher throughput, and using a lower amount of sample, than using GC/C/IRMS.

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Section: N-isotopic Enrichmentsmentioning

confidence: 99%

Simultaneous measurement of ¹³C‐ and ¹⁵N‐isotopic enrichments of threonine by mass spectrometry

Godin

Mermoud

Rémond

et al. 2009

Rapid Comm Mass Spectrometry

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“…The N-pentafluorobenzoyldi-n-butylamide derivative of taurine has also been employed in the GC-MS analysis of enriched [1,[2][3][4][5][6][7][8][9][10][11][12][13] C]-and [ 15 N]taurine. 19,20 Although this derivative has good chromatographic properties, not only is there the addition of one exogenous nitrogen atom but the fluorine released upon combustion of the N-trifluoroacetyl-i-propyl (TFA-IP) esters would poison the oxidation reactor Pt catalyst surface, resulting in the irreversible conversion of Cu and Ni into the stable metal halides Cu 2 F and Ni 2 F, respectively. 21,22 Further combustion interface problems have been noted, including deterioration of the fused-silica capillaries and T-pieces down-stream of the combustion reactor, a possible consequence of gaseous HF being produced during TFA-IP ester combustion.…”

mentioning

confidence: 99%

Determination of the natural abundance δ¹⁵N of taurine by gas chromatography–isotope ratio measurement mass spectrometry

Téa

Antheaume

Besnard

et al. 2010

Rapid Comm Mass Spectrometry

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The measurement of the nitrogen isotope ratio of taurine (2-aminoethanesulphonic acid) in biological samples has a large number of potential applications. Taurine is a small water-soluble molecule which is notoriously difficult to analyze due to its polarity and functionality. A method is described which allows the determination of the natural abundance δ(15)N values of taurine and structural analogues, such as 3-amino-1-propanesulphonic acid (APSA), by isotope ratio mass spectrometry interfaced to gas chromatography (GC-irm-MS). The one-step protocol exploits the simultaneous derivatization of both functionalities of these aminosulphonic acids by reaction with triethylorthoacetate (TEOA). Conditions have been established which ensure quantitative reaction thus avoiding any nitrogen isotope fractionation during derivatization and workup. The differences in the δ(15)N values of derivatized and non-derivatized taurine and APSA all fall within the working range of 0.4‰ (-0.02 to 0.39‰). When applied to four sources of taurine with various δ(15)N values, the method achieved excellent reproducibility and accuracy. The optimized method enables the determination of the natural abundance δ(15)N values of taurine over the concentration range 1.5-7.84 µmol.mL(-1) in samples of biological origin.

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Determination of the concentration of nitrogenous bio-organic compounds using an isotope ratio mass spectrometer operating in continuous flow mode

et al. 2011

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The quality of the determination of compound-specific isotopic content at natural abundance by gas chromatography-isotope ratio measurement-mass spectrometry (GC-irm-MS) relies on the stability of the voltage generated by the ion detector Faraday cages. The application of GC-irm-MS to the determination of δ(13)C (‰) and δ(15)N (‰) is now routine. However, for numerous applications, it is necessary to determine both the isotope content (δ(15)N) and the quantity (in micromoles) of analyte present. We now show that it is possible for nitrogen-containing compounds to measure how much analyte is present with an irm mass spectrometer linked to a GC by exploiting the integrated N(2) total ion current intensity (Vs) generated by measuring the (15)N/(14)N isotope ratio. The method is validated over a range of concentration (2-70 mmol/L) and δ(15)N (-70 to +50‰) values for six molecules of diverse chemical nature and functionality (nortropine, norpseudotropine, nortropinone, cysteine, taurine, glutathione). It is shown that once the ion current is calibrated, the quantitative values are of a comparable quality to those obtained from GC with flame ionization detection (GC-FID). In addition, it is demonstrated that over a definable range, the δ(15)N (‰) value is independent of the quantity of analyte introduced, confirming the validity of this method.

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Evaluation of Taurine Metabolism in Cats by Dual Stable Isotope Analysis

Cited by 6 publications

References 21 publications

Simultaneous measurement of ¹³C‐ and ¹⁵N‐isotopic enrichments of threonine by mass spectrometry

Simultaneous measurement of ¹³C‐ and ¹⁵N‐isotopic enrichments of threonine by mass spectrometry

Determination of the natural abundance δ¹⁵N of taurine by gas chromatography–isotope ratio measurement mass spectrometry

Determination of the concentration of nitrogenous bio-organic compounds using an isotope ratio mass spectrometer operating in continuous flow mode

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Evaluation of Taurine Metabolism in Cats by Dual Stable Isotope Analysis

Cited by 6 publications

References 21 publications

Simultaneous measurement of 13C‐ and 15N‐isotopic enrichments of threonine by mass spectrometry

Simultaneous measurement of 13C‐ and 15N‐isotopic enrichments of threonine by mass spectrometry

Determination of the natural abundance δ15N of taurine by gas chromatography–isotope ratio measurement mass spectrometry

Determination of the concentration of nitrogenous bio-organic compounds using an isotope ratio mass spectrometer operating in continuous flow mode

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Simultaneous measurement of ¹³C‐ and ¹⁵N‐isotopic enrichments of threonine by mass spectrometry

Simultaneous measurement of ¹³C‐ and ¹⁵N‐isotopic enrichments of threonine by mass spectrometry

Determination of the natural abundance δ¹⁵N of taurine by gas chromatography–isotope ratio measurement mass spectrometry