Feeding a 14%
coconut oil/0.5%
cholesterol (CNO/chol) diet to rabbits resulted in plasma
triglycerides that were, on average, 15 times higher than basal levels. Plasma
triglycerides in rabbits fed a 14%
olive oil/0.5%
cholesterol (OO/chol) diet were significantly below baseline levels. Differences in postprandial
triglyceride response and postheparin plasma
lipoprotein lipase activity (LPL) in various feeding conditions were studied to determine the mechanism of the
hypertriglyceridemia. Postprandial
triglyceride responses after the first high fat/
cholesterol meal were more prolonged in CNO/chol rabbits than in OO/chol rabbits; postprandial
triglyceride responses after chronic CNO/chol feeding were significantly greater compared to OO/chol rabbits. When long-term CNO/chol rabbits were given one OO/chol or
corn oil/chol meal, postprandial
triglyceride peaks were greatly diminished, suggesting that these
unsaturated fat meals may alter
triglyceride clearance capacity. LPL activity was 400% higher than basal levels in chronically fed OO/chol rabbits but changed very little in chronically fed CNO/chol rabbits. Twenty-four hours after a single OO/chol meal was fed to chow-fed rabbits, LPL doubled; one CNO/chol meal was associated with only a 40% increase. Feeding a single OO/chol or
corn oil/chol meal to chronically fed CNO/chol rabbits resulted in a 30% to 50% increase in LPL by 24 hours. Thus, the
hypertriglyceridemia in CNO/chol rabbits may result in part from a decreased clearance capacity due to a lack of increase in LPL activity, while increased LPL may be partially responsible for the hypotriglyceridemia observed in OO/chol feeding. Aortic
cholesterol was substantially higher in CNO/chol rabbits.
Triglyceride was approximately eight times greater in livers from CNO/chol-fed rabbits than in those fed OO/chol, but liver
cholesterol was only about one-third as much as that in OO/chol rabbits.