Fig. 2.

Amounts of ceramide species (A) and sphingolipid bases and their 1-phosphates (B) in HDL2 and HDL3 lipoprotein subfractions. HDL subfractions were isolated from plasma pools (N = 6), each obtained by combining blood from three normolipidemic donors. The assignment for ceramide subspecies is based on the amide-linked fatty acid found in the molecule. Values shown are mean ± SEM. Note the use of a logarithmic scale on the ordinate in panel A. ^*P < 0.05 for paired t-test of data for HDL2 versus HDL3. Abbreviations: DH-Sph, dihydrosphingosine; DH-S1P, dihydrosphingosine-1-phosphate; DHC16, dihydroceramide linked to C16 fatty acid; S1P, sphingosine-1-phosphate; Sph, sphingosine.