TABLE 7.

Levels of SM, Cer, Sph, dhSph, S1P, and dhS1P in human lipoproteins and plasma

	SM		Cer		Sph		dhSph		S1P		dhS1P
Lipoprotein Classa	nmol/ml	%	nmol/ml	%	pmol/ml	%	pmol/ml	%	pmol/ml	%	pmol/ml	%	Particle Concentration (nmol/ml)(29)
VLDL	15.3	3.15	0.685	8.73	2.32	2.30	1.62	2.72	13.8	1.33	1.62	4.94	0.073 ± 0.06
LDL	159.4	32.85	3.134	39.94	32.39	32.06	24.17	40.63	38.8	3.73	4.46	13.59	1.514 ± 0.48
HDL2	165.5	34.10	2.255	28.74	17.89	17.71	13.39	22.51	169.5	16.30	5.87	17.89	8.350 ± 4.60
HDL3	145.1	29.90	1.772	22.59	48.42	47.93	20.31	34.14	817.6	78.64	20.86	63.58	22.10 ± 5.70
Total	485.3	100.0	7.846	100.0	101.02	100.0	59.49	100.0	1039.7	100.0	32.81	100.00

Values are mean ± SE, n = 3 pooled plasma samples, except for Cer, Sph, dhSph, S1P, and dhS1P in HDL₂ and HDL₃, n = 8 pooled plasma samples. Blood was pooled from 3 or 4 donors in the presence of EDTA, chloramphenicol, gentamycin sulfate, epsilon amino-caproic acid, and dithiobisnitrobenzoic acid.

^aTo calculate values per ml plasma, sphingolipid concentration in lipoprotein particles from Table 6 was multiplied by the lipoprotein particle concentration (nmol/ml) (29).