Atherosclerosis in low density lipoprotein receptor knockout mice fed cholesterol and soybean oil

In order to study aortic atherosclerosis and atherosclerotic response to di etary cholesterol and soybean oil in homozygous LDLR-/- mice, the 16 weeks old animals were randomized in 4 groups either fed standard diet (no choles terol added, group I, 12 male and 12 female), standard diet added 0.5% chol esterol (group II, 12 male and 12 female), standard diet added 10% soybean oil (group Iii, 7 male) or standard diet added 0.5% cholesterol and 10% soy bean oil (group IV, 7 male) for 14 weeks. At termination, the plasma choles terol of males was: 9.4 mmol/I +/- 0.3 (SD) (group I), 34.4 +/- 6.2 (group II), 9.9 +/- 0.07 (group III), 32.6 +/-0.1 (group IV), and of females 6.9 /- 2.7 (group I) and 31.7 +/- 4.4 (group II). No apparent difference in pla sma triglyceride levels was observed between the groups of either sexes. Ao rtic atherosclerosis (ratio intima/media) in males was 0.17 +/- 0.09 (SD) ( group I), 0.96 +/- 0.32 (group II, p<0.05 compared to other male groups), 0 .21 +/- 0.09 (group III), and 0.59 +/- 0.34 (group IV, p<0.05 compared to o ther male groups), and in females 0.12 +/- 0.08 (group I) and 0.83 +/- 0.30 (group II, p<0.05 compared to female group I). No sex difference in the ra tio intima/media was recorded for LDLR-/- mice on standard or cholesterol d iet. It was concluded that spontaneous hypercholesterolemia and aortic athe rosclerosis in LDLR-/- mice were significantly increased by 0.5% cholestero l addition to the standard diet but were not affected by 10% soybean oil ad dition to the standard diet, and that 10% soybean oil addition to the 0.5% cholesterol diet did not affect cholesterol induced hypercholesterolemia bu t significantly decreased cholesterol induced aortic atherosclerosis. (C) 1 999 Elsevier Science Inc.