Sphinosine 1-phosphate (S1P) is an active byproduct of sphingomyelin metabolism. All cells can synthesize this biomolecule but the majority of its synthesis comes from erythrocytes and endothelial cells. In cases of inflammation, mast cells and platelets are the main source of sphingosine 1-phosphate. S1P cellular functions could be intracellular, where it is synthesized. In addition, upon secretion, it circulates in the blood via its binding to high-density lipoproteins and albumin. When S1P reaches its target cell it could activate 5 different high affinity receptors belonging to the G-protein coupled receptor superfamily: Sphingosine 1-phosphate receptors, termed S1PR1-5.S1PR3 is specifically detected in the brain, heart, spleen, liver, lung, thymus, kidney, testis and skeletal muscle3. S1PR1 and S1PR2 are generally expressed in the CNS, cardiovascular and immune systems1. S1PR4 is specifically expressed in the lymphoid tissue and S1PR5 in natural killer cells and olygodendrocytes