Method(s): LC-MS/MS (1).
Roles of arginine
The basic amino acid arginine serves as an essential precursor for the synthesis of biological important molecules including ornithine, proline, polyamines, creatine, glutamate, homoarginine, methylated arginines (ADMA and SDMA) and nitric oxide (NO) (2). NO is an important ubiquitous gaseous signalling molecule involved in vasodilation, platelet aggregation, inflammation and neurotransmission. Although NO synthesis accounts for a small fraction of total arginine utilization, there is a dose-response-relationship between NO synthesis and arginine intake, a relationship that is expected to be strong in subjects with low basal NO synthesis, as in many pathological conditions. The arginine-NO system has been studies in variety of conditions, including cardiovascular disease, hypertension, preeclampsia, diabetes, insulin resistance and obesity.
Performance of the assay
Lower limit of detection (LOD): 0.10 µmol/L.
Within-day CV: 6-7 %; between-day CV: 5-8 %.
Should be measured together with asymmetric dimethylarginine (and homoarginine) for the assessment of endothelial function and cardiovascular risk.
Specimen, collection and processing
Patient/subject: Prandial status affects concentration, which increases after arginine intake.
Matrix: EDTA plasma and serum. Arginine decreases (up to 70%) in samples with hemolysis.
Volume: Minimum volume is 50 µL, but 200 µL is optimal and allows reanalysis.
Preparation and stability: The blood sample must be centrifuged and the plasma/serum fraction put on ice, and frozen.
Transportation; for general instruction on transportation, click here.
Frozen, on dry ice.
Reported values, interpretation
Reported values: 10-80 µmol/L
Intraclass correlation coefficient (ICC): 0.53.
1. Midttun, O., Kvalheim, G., and Ueland, P.M. (2013). High-throughput, low-volume, multianalyte quantification of plasma metabolites related to one-carbon metabolism using HPLC-MS/MS. Anal Bioanal Chem 405, 2009-017.
2. Morris, S.M. (2016). Arginine metabolism revisited. J Nutr 146, 2579S-586S.