Characterization of triglyceride rich lipoproteins with very light density by ultracentrifugation and agarose gel electrophoresis using triglyceride- and cholesterol-staining.

Hypertriglyceridemia is an independent risk factor for atherosclerosis. This risk is most likely due to accumulation of circulating triglyceride rich lipoproteins with heterogeneous particles. The identification and characterization of these triglyceride rich lipoproteins is important to detect abnormality of triglyceride metabolism. In the present study, we developed a new method that combines ultracentrifugation and agarose gel electrophoresis with triglyceride- and cholesterol-staining. We investigated 40 subjects with hypertriglyceridemia. Triglyceride rich lipoproteins with very light density were recovered in the aqueous fraction after ultracentrifugation (17,000 x g, 15 min). The lipoproteins recovered in the aqueous fraction contained chylomicrons, if present, their remnants, and light-VLDL (d <1.000 g/ml) containing apoB-100, but not normal VLDL (d <1.006 g/ml) and IDL. Triglyceride rich lipoproteins in the aqueous fraction were characterized by electrophoresis patterns of triglyceride- and cholesterol-staining. Forty patients with hypertriglyceridemia were separated into 8 groups according to their electrophoretic patterns. In lipoproteins recovered in the aqueous fraction from each group, the triglyceride level was correlated with the respective cholesterol level. In summary, a system using ultracentrifugation and agarose gel electrophoresis with triglyceride- and cholesterol-staining is useful for characterization of triglyceride rich lipoproteins and their remnants.