The effects of fat emulsion (Intralipid®) on HDL in primary hypertriglyceridemia were studied in vivo. Following a 14-h fast, five primary hypertriglyceridemic male patients (HTG) and six healthy male subjects (N) received intralipid® over a 4-h infusion. Apo A-I and A-II in HDL2 and HDL3 were estimated and polyacrylamide gradient gel electrophoresis of lipoprotein (density<1.225g/ml) was performed before, at 4h and 6h after the start of the infusion. HDL subpopulations were observed using terminology by Blanche et al.
At 4h, Apo A-I and A-II in HDL2 increased significantly, while HDL3 decreased significantly. Significant increases were noted in HDL2b and HDL2a percentages and significant decreases in HDL3a and HDL3b. However, most of these dramatic changes at 4h disappeared by 6h.
In HTG at 4h and 6h, no significant changes of apo A-I and A-II i n both HDL2 and HDL3 were observed. In addition, no changes in HDL2b and HDL3a percentages were observed in HTG at 4h. However, three large HDL peaks were revealed by stained gel densitometry. The degree of change in particle size over time of HDL occupying peak 2 and peak 3 was less for HTG than N.
These results suggest that reverse conversion between HDL2 and HDL3 over time and among HDL subpopulations is impaired in HTG.
