CHOLESTEROL RESPONSE AND FATTY STREAK FORMATION IN HAMSTERS FED 2 LEVELS OF SATURATED FAT AND VARIOUS LEVELS OF CHOLESTEROL

Two levels of saturated fat (31 and 39% of calories) and several level s of cholesterol were fed for 12 weeks to weanling male hamsters in or der to evaluate their cholesterolemic response and fatty streak format ion in the aortic arch. Diets contained 5% cellulose, 20% casein, and 15% butterfat plus 0, 0.05, 0.5 or 3% cholesterol (C), or 20% butterfa t plus 0 or 0.5% C. Total plasma cholesterol (TC) was significantly (P less than or equal to 0.05) elevated when dietary C was increased to 0.54% or higher with either fat diet compared with no or low C added d iets (542-789 vs 282-315 mg/dl). With 3.04% C, plasma cholesterol valu es were significantly higher than with 0.54 or 0.56% C in diets contai ning either 15 or 20% fat (789 vs 542 or 623 mg/dl, respectively). Inc reased TC was mainly due to significant elevations in VLDL and LDL cho lesterol levels, which resulted in a significant decrease in HDL/LDL c holesterol ratios. Reductions in HDL/LDL cholesterol ratios were simil ar in hamsters fed 15% fat with 0.54 or 3.04% cholesterol or 20% fat w ith 0.56% cholesterol. Liver cholesterol increased significantly with all diets containing added C. Fatty streak formation was significantly greater in animals fed 0.54, 0.56 or 3.04% added cholesterol with 15 or 20% fat diet compared with low (0.04 or 0.09%) C diets. Significant plasma and liver cholesterol elevations, low HDL/LDL cholesterol rati os and increased fatty streak formation along with lower metabolic str ess suggest that a semipurified diet containing 15% fat and 0.54% C is appropriate for the development of type II or advanced lesions of ath erosclerosis for progression and regression studies in hamsters. Publi shed by Elsevier Science Inc.