Plasma sphingosine-1-phosphate concentration is reduced in patients with myocardial infarction.

The sphingolipid sphingosine-1-phosphate (S1P) plays an important role in protecting the heart against ischemia-reperfusion injury. S1P is normally present in human plasma. However, there are no data available on the effect of myocardial infarction on the plasma concentrations of S1P and related sphingolipids. The aim of this study was to examine the concentrations of SIP, sphinganine-1-phosphate, free sphingosine, free sphinganine, and ceramide in the plasma of patients after myocardial infarction. The study was performed on two groups of male subjects: controls with no specific complaints (n=21) and patients who had had acute myocardial infarction (n=22). In the latter group, blood was taken immediately after admission to the hospital and five days later. The concentrations of the above compounds were measured by high-pressure liquid chromatography. The concentrations of SIP and sphinganine-1-phosphate were reduced by ca. 50% both early after infarction and five days later. The concentrations of the other compounds were not affected by myocardial infarction. The reduction in plasma concentration of S1P after infarction could lessen its protective action on cardiomyocyte viability. The observed reduction in S1P level might be associated with the standard antiplatelet treatment given to patients since thrombocytes are one of the major sources of plasma S1P.