Cellular pathology of progressive atherosclerosis in the WHHL rabbit. An animal model of familial hypercholesterolemia.

Abstract
This report describes the features of developing atherosclerosis in the Watanabe heritable hyperlipidemic (WHHL) rabbit, an animal model of human familial hypercholesterolemia. Observations were made in 18 homozygous WHHL rabbits, aged 4 days to 15 months, fed standard rabbit chow; seven control New Zealand white rabbits fed a similar diet, and four New Zealand white rabbits fed rabbit chow containing 2% cholesterol and 10% corn oil for 2 weeks. The WHHL rabbits showed evidence of progressive disease of the aorta with accumulation of strongly birefringent lipid in intimal lesions, including fatty streaks, raised foam cell lesions, and plaques (atheromas), as well as in the media. As seen by electron microscopy, the cellular population of the intimal lesions consisted predominantly of smooth muscle cells with lipid deposits and lipid-laden foam cells. Lipid deposits occurred as cytoplasmic neutral lipid droplets and as multilamellar bodies. In addition to advanced atherosclerosis of the aorta, a 15-month-o...