Notes on the breeding of the WHHL rabbit: an animal model of familial hypercholesterolemia.

We describe in this study a reliable method for the breeding of the Watanabe heritable hyperlipidemic (WHHL) rabbit. Placing a male and a female WHHL rabbit in the same cage for the purpose of mating resulted in only two pregnancies out of a total of 227 mating attempts (0.9%). After manually assisting the rabbits, 15% of the matings resulted in pregnancies. When the female rabbits were injected with 40 I.U. of human chorionic gonadotropin within 1 hr of this procedure, 56% of the matings resulting in pregnancies. We feel that the inherent difficulty in breeding the WHHL rabbit, a model for the disease familial hypercholesterolemia, can be significantly overcome by the methods discussed in this report.