کد مقاله | کد نشریه | سال انتشار | مقاله انگلیسی | نسخه تمام متن |
---|---|---|---|---|
1214335 | 1494158 | 2010 | 6 صفحه PDF | دانلود رایگان |
![عکس صفحه اول مقاله: Analysis of [2H7]methionine, [2H4]methionine, methionine, [2H4]homocysteine and homocysteine in plasma by gas chromatography–mass spectrometry to follow the fate of administered [2H7]methionine Analysis of [2H7]methionine, [2H4]methionine, methionine, [2H4]homocysteine and homocysteine in plasma by gas chromatography–mass spectrometry to follow the fate of administered [2H7]methionine](/preview/png/1214335.png)
Homocysteine plays a key role in several pathophysiological conditions. To assess the methionine–homocysteine kinetics by stable isotope methodology, we developed a simultaneous quantification method of [2H7]methionine, [2H4]methionine, methionine, [2H4]homocysteine and homocysteine in rat plasma by gas chromatography–mass spectrometry (GC–MS). [13C]Methionine and [13C]homocysteine were used as analytical internal standards to account for losses associated with the extraction, derivatization and chromatography. For labeled and non-labeled homocysteine measurements, disulfide bonds between homocysteine and other thiols or proteins were reduced by dithiothreitol. The reduced homocysteine and methionine species were purified by cation-exchange chromatography and derivatized with isobutyl chlorocarbonate in water–ethanol–pyridine. Quantification was carried out by selected ion monitoring of the molecular-related ions of N(O,S)-isobutyloxycarbonyl ethyl ester derivatives on the chemical ionization mode. The intra- and inter-day precision of the assay was less than 6% for all labeled and non-labeled methionine and homocysteine species. The method is sensitive enough to determine pharmacokinetics of labeled methionine and homocysteine.
Journal: Journal of Chromatography B - Volume 878, Issues 3–4, 1 February 2010, Pages 417–422