| Autor: |
Reijngoud, DJ, Hellstern, G, Elzinga, H, de Sain-van der Velden, MG, Okken, A, Stellaard, F |
| Přispěvatelé: |
Faculteit Medische Wetenschappen/UMCG |
| Jazyk: |
angličtina |
| Rok vydání: |
1998 |
| Předmět: |
|
| Zdroj: |
Journal of Mass Spectrometry, 33(7), 621-626. Wiley |
| ISSN: |
1076-5174 |
| Popis: |
A method was developed for measuring protein fractional synthetic rates using the N-methoxycarbonylmethyl ester (MCM) derivative of L-[1-C-13]valine and on-line gas chromatography/combustion/isotope ratio mass spectrometry (GC/C/IRMS). The derivatization procedure can be performed rapidly and GC separation of valine from the other branched-chain amino acids, leucine and isoleucine, is easily obtained. A good lineair relationship was observed between the increment of the C-13/C-12 isotope ratio in CO, gas derived from the combustion-of derivatized valine and the tracer mole ratio of L-[1-C-13]valine to unlabelled valine. The limit of quantitation was at an L-[1-C-13]valine tracer mole ratio of 0.0002. The method was used to measure the isotopic enrichment of L-[1-C-13]valine-in standard mixtures and in skeletal muscle of six growing piglets infused with L-[1-C-13]valine (2 mg kg(-1) h(-1) for 6 h). After infusion of L-[1-C-13]valine the mean tracer mole ratio in plasma of L-[1-C-13]valine at the isotopic steady state was 0.0740 +/- 0.0056 (GC/MS, mean +/- SEM) and the mean tracer mole ratio of valine in muscle protein fraction at 6 h was 0.000236 +/- 0.000038 (GC/C/IRMS). The resulting mean protein fractional synthetic rate in piglet skeletal muscle was 0.052 +/- 0.007% h(-1), which is in good agreement with literature data obtained with alternative, more elaborate techniques. By this method protein fractional synthetic rates Can be measured at low isotopic enrichment levels using L-[1-C-13]valine, the MCM derivative and on-line GC/C/IRMS. (C) 1998 John Whey & Sons, Ltd. |
| Databáze: |
OpenAIRE |
| Externí odkaz: |
|
Plný text