N,N-DIMETHYLSPHINGOSINE PHOSPHORYLATION IN HUMAN PLATELETS

Metabolism of sphingosine (Sph) derivatives in human platelets was exa mined. [H-3]Sph was rapidly and heavily phosphorylated into sphingosin e l-phosphate, similarly in resting and stimulated platelets, [C-14]N, N-dimethylsphingosine was stable in resting platelets, while it was co nverted into N,N-dimethylsphingosine 1-phosphate (DMS-I-P), although w eakly, in platelets stimulated with thrombin or 12-O-tetradecanoylphor bol 13-acetate. This DMS-1-P formation was inhibited by staurosporine, a potent protein kinase inhibitor, [H-3]C-2-ceramide was unchanged bo th in resting and stimulated platelets, Our report is the first to des cribe production of DMS-1-P in a biological system. (C) 1995 Academic Dress.