The effect of selective breeding on the development of coronary atherosclerosis in WHHL rabbits. An animal model for familial hypercholesterolemia.

To increase the incidence of coronary atherosclerosis in Watanabe heritable hyperlipidemic (WHHL) rabbits, an animal model for familial hypercholesterolemia, selective breeding has been carried out. The results obtained are as follows: The incidence of coronary atherosclerosis before selective breeding was 21.8%, whereas that after the breeding was 58.9% (average values for rabbits between 4 and 12 months old), showing that the incidence of coronary atherosclerosis can be increased by an appropriate breeding technique. With respect to the relationships between parents and offspring, if parents had coronary atherosclerosis, then the incidence of the disease in the offspring was 83.3%; therefore the disease was strongly heritable. The mean total cholesterol (TC) and triglyceride (TG) levels of the colony before selective breeding were 579 +/- 163 mg/dl and 471 +/- 144 mg/dl, respectively, while those after the breeding were 665 +/- 151 mg/dl and 603 +/- 178 mg/dl; serum lipid levels increased in parallel with incidence of coronary atherosclerosis. The earliest development of coronary atherosclerosis in the colony after selective breeding was found in 4-month-old rabbits and the whole colony suffered from the disease at 18 months of age.