Extraction and Quantification of Sphingosine 1-Phosphate (S1P)

Sphingosine 1-phosphate (S1P) is a lipid metabolite and signaling molecule involved in many different physiological processes including lymphocyte circulation, T cell differentiation, antigen presentation, and maintenance of the vascular endothelial barrier. S1P is a ligand of five different G protein-coupled cell surface receptors designated S1P1-5. It has also been described as an intracellular second messenger. Quantification of S1P in biological samples is therefore an important task to decipher its signaling capabilities in vivo under physiological and pathophysiological conditions in different body fluids and organs. In this protocol, quantification of S1P is performed by liquid chromatography coupled to triple-quadrupole mass spectrometry (LC-MS/MS).