Effect of dietary omega-3 fatty acid on serum lipids, platelet function, and atherosclerosis in Watanabe heritable hyperlipidemic rabbits.

Omega-3 fatty acids have been shown to lower plasma cholesterol and triglyceride concentrations in humans. However, the effects of these fatty acids on the interactions among lipid concentrations, platelet activity, and atherogenesis have not been characterized in humans or in animals with low density lipoprotein (LDL) receptor deficiencies. To test the hypothesis that omega-3 fatty acids exert a protective effect in LDL receptor-deficient animals by lowering hyperlipidemia, reducing platelet aggregation, and reducing the severity of atherosclerosis, we evaluated young homozygous Watanabe heritable hyperlipidemic (WHHL) rabbits that were fed omega-3 fatty acids. One-month-old male and female WHHL rabbits were placed on either a control diet (standard laboratory rabbit chow) or a diet supplemented with Menhaden fish oil (MFO), which contained eicosapentaenoic acid (EPA). Consumption measurements during the 5 months of the study indicated that the MFO-fed group received 150 to 200 mg/kg/day of EPA. Six-month-old, MFO-fed, female WHHL rabbits had significantly lower plasma concentrations of total cholesterol (582 +/- 20 mg/dl vs. 856 +/- 44 mg/dl, control, p less than 0.05) and triglycerides (266 +/- 21 mg/dl vs. 459 +/- 15 mg/dl, control, p less than 0.05), with lower serum/plasma lipoprotein concentrations [very low density lipoprotein (VLDL), LDL, high density lipoprotein (HDL)] compared to control female WHHL rabbits. Male MFO-fed rabbits had only significantly lower VLDLs (46 +/- 9 mg/dl) compared to control male WHHL rabbits (156 +/- 9 mg/dl, p less than 0.05).(ABSTRACT TRUNCATED AT 250 WORDS)