A comparative study on serum lipids and atherosclerotic plaque formation in diet-induced and familial hypercholesterolemia in rabbits, and the effect of partial ileal bypass.

Aim of the present study was to compare an alimentary and a hereditary rabbit model for hypercholesterolemia. Serum lipids, serum lipoproteins and distribution and prevention of atherosclerotic plaque formation were studied in (1%) cholesterol-fed NZW rabbits and both heterozygous and homozygous WHHL rabbits. Cholesterol-fed NZW rabbits showed a hypercholesterolemia without hypertriglyceridemia, caused by accumulation of a spectrum of cholesterol ester-rich beta-migrating lipoproteins with a relatively low density. The WHHL rabbits displayed both a hypercholesterolemia with an elevation of LDL, and a hypertriglyceridemia. The hypertriglyceridemia in the WHHL homozygotes was due to accumulation of VLDL remnants and in the heterozygotes to a slight rise in normal pre-beta VLDL. Despite the pronounced quantitative and qualitative differences in lipoproteins, the location and extent of atherosclerotic plaques which had developed after 13 weeks cholesterol-rich diet in NZW rabbits and in 10 months old homozygous WHHL rabbits, was quite similar. Partial ileal bypass surgery lowered serum cholesterol in all three groups and also prevented atherogenesis.