Species Differences of Serum and Liver Cholesterol Levels between Rabbits and Rats Fed on High-cholesterol Diet.

高折 修二 ・島本 暉朗 The experimental atheromatosis in various animals fed on high-fat, high-cholesterol diet has widely been used for the elucidation of the pathogenesis of clinical arterioscle rosis and for the laboratory evalution of lipolytic agents. Page et al. (1) and Myasnikov (2) have shown that rabbits are highly susceptive to the exogenously administered cho lesterol, while rats are relatively resistant to the effect of cholesterol feedings. For the sake of producing the increased level of serum cholesterol and the aortic atheromatosis in rats, the feeding of the animal on high-cholesterol diet mixed with cholic acid or taurocholic acid has been recommended (1, 3, 4). In comparative studies on the effects of lipolytic agents in rabbits, rats and chicken, Loustalot et al. (5) have emphasized that it is impossible to generalize a conclusion from experimental results of lipolytic agents obtained in one species. In the course of a series of studies on the hypolipemic effects of thyroxine deriva tives in rats and rabbits fed on high-cholesterol diet, the authors have noticed marked differences of serum and liver cholesterol levels between both species. These differences are likely to give an important clue to know the cholesterol metabolism and also the mode of action of lipolytic agents in both species.