An improved semisynthetic atherogenic diet for rabbits. Dietary fat-carbohydrate interaction in atherogenesis
Wilson, R.B.; Newberne, P.M.; Conner, M.W.
Archives of Pathology 96(5): 355-359
1973
ISSN/ISBN: 0363-0153 PMID: 4741906 Document Number: 69181
Four groups of male Dutch rabbits were fed on semisynthetic diets A, B, C and D. Diets A and B had more carbohydrate and less fat than diets C and D. The ratio of low polyunsaturated fatty acid to saturated fatty acid was 0.32 for A, 6.20 for B, 0.24 for C and 6.20 for D. All diets had the same cholesterol:energy ratio. A control group of rabbits was fed on laboratory chow. The rabbits were killed after 24 weeks on these diets.Weight gain closely paralleled energy intake in all 4 groups and in controls. Serum lipid concentrations were generally higher in rabbits on semisynthetic diets than those on chow, the highest values being in groups A and C. Lipid accumulation occurred only in arteries. Intimal lipid was absent from the arteries of controls and almost absent from those of groups B and D. In groups A and C lipid streaks covered more than 40% of the intimal aortic surfaces. Individual aortic atherosclerotic scores correlated positively with serum cholesterol concentrations. Arterial lesions produced in groups A and C were similar to those of early human atherosclerosis. Aortic and coronary atherosclerosis was more extensive in rabbits given butter at 44 or 25% of total energy intake than those given maize oil. Saturated fats appeared to be atherogenic only in synthetic diets and not when added to chow. Excess carbohydrate did not appear to have an atherogenic effect.