Plasma cholesterol levels, atherosclerosis and liver damage in rabbits fed cyclopropenoid fatty acids

Graduation date: 1974In this five-week feeding study male New Zealand rabbits were\ud fed diets containing cyclopropene fatty acids (CPFA), diets containing\ud cholesterol, and diets with both CPFA and cholesterol added to test\ud the effect of CPFA on cholesterol metabolism and atherosclerosis\ud induction. When CPFA-fed animals were compared with control\ud animals, they tended to have higher plasma cholesterol levels, higher\ud liver cholesterol levels and a high incidence of aortic atherosclerosis.\ud Control animals had no atherosclerosis. A similar pattern was seen\ud when animals fed cholesterol were compared with those fed both\ud cholesterol and CPFA. Mean triglyceride levels were higher in\ud CPFA-fed rabbits than in controls.\ud A wide range of sensitivity to the CPFA was observed. Some\ud animals had plasma cholesterol levels eight to ten times normal after\ud three weeks of feeding; others showed only slight changes after five weeks. Histological examination of liver cells from CPFA-fed animals\ud showed evidence of alteration in cellular morphology and, in some\ud cases, extensive damage. In some liver cells of CPFA-fed rabbits,\ud subcellular organelles appear to be aligned in fiber-like structures.\ud The most extreme signs of toxicity were noted in livers of rabbits fed\ud CPFA and cholesterol.\ud After five weeks on experimental diets, adipose tissue of the\ud rabbits contained approximately 2% CPFA. Ratios of 16:0 to 16:1 and\ud 18:0 to 18:1 fatty acids increased in liver lipid and erythrocyte ghost\ud lipid after CPFA feeding. Over the five-week study there were no\ud differences in rate of weight gain or in feed conversion ratios in\ud CPFA-fed animals