| Method |
After 24 hr incubation in serum-free MEM in the presence and absence of insulin (1 pg/ml), the concentrations of triglycerides and cholesterol in the medium were determined by gas-liquid chromatography. Triglycerides and cholesterol contents of concentrated culture medium, lipoprotein density classes, and HepG2 cells were determined as described by Kuksis et al. (46). The concentrations of apolipoproteins A-I, A-II, B, C-I, C-II, C-III, and E were measured by electroimmunoassays developed in researchers' laboratory as previously described (47-51). |