Abstract
The apoprotein C composition of very low density lipoprotein (VLDL) were studied in 30 male patients with angiographically defined coronary artery disease (CAD). The tetramethylurea soluble VLDL apoproteins were separated by polyacrylamide gel electrophoresis and the relative proportions of apo CII, CIII1 and CIII2 were determined.
The CAD group had significantly lower apo CII/CII+CIII ratio (%apo CII) andhigher plasma triglyceride (TG) level than the age-matched control group. There were good correlations between the plasma TG level and % apo CII in each group. The regression lines were Y=-0.0614X+24.48 for the CAD males, and Y=-0.0319X+25.65 for the control males. The regression slope for the CAD group was steeper than the control group. The intercepts at 100mg/dl plasma TG were 22.3% apo CII for the CAD males, and 22.5 for the control males. However, the intercepts at 300mg/dl plasma TG were 10.1% apo CII for the CAD males, and 16.1 for the control males, and the difference was significant.
Twenty-two male relatives of the CAD patients were also investigated. They had no significant differences in VLDL apoprotein C composition from the controls.
These results suggest that hypertriglyceridemia associated with decreased % apo CII is related to coronary atherogenesis. Decreased % apo CII in VLDL might have inhibitory effects on lipoprotein lipase activity and this would disturb VLDL catabolism and accumulate VLDL remnant particles or intermediate density lipoproteins.
