Article ID | Journal | Published Year | Pages | File Type |
---|---|---|---|---|
10550023 | Journal of Chromatography B | 2009 | 6 Pages |
Abstract
S-Adenosylmethionine (SAM) serves as a methyl donor in biological transmethylation reactions. S-Adenosylhomocysteine (SAH) is the product as well as the inhibitor of transmethylations and the ratio SAM/SAH is regarded as the measure of methylating capacity (“methylation index”). We present a rapid and sensitive LC-MS/MS method for SAM and SAH determination in mice tissues. The method is based on chromatographic separation on a Hypercarb column (30 mm Ã 2.1 mm, 3 μm particle size) filled with porous graphitic carbon stationary phase. Sufficient retention of SAM and SAH on the chromatographic packing allows simple sample preparation protocol avoiding solid phase extraction step. No significant matrix effects were observed by analysing the tissue extracts on LC-MS/MS. The intra-assay precision was less than 9%, the inter-assay precision was less than 13% and the accuracy was in the range 98-105% for both compounds. Stability of both metabolites during sample preparation and storage of tissue samples was studied: the SAM/SAH ratio in liver samples dropped by 34% and 48% after incubation of the tissues at 4 °C for 5 min and at 25 °C for 2 min, respectively. Storage of liver tissues at â80 °C for 2 months resulted in decrease of SAM/SAH ratio by 40%. These results demonstrate that preanalytical steps are critical for obtaining valid data of SAM and SAH in tissues.
Keywords
Related Topics
Physical Sciences and Engineering
Chemistry
Analytical Chemistry
Authors
Jakub Krijt, Alena Dutá, Viktor Kožich,