Cholesterol-fed and casein-fed rabbit models of atherosclerosis - Part 1: Differing lesion area and volume despite equal plasma cholesterol levels

Abstract

One-month-old male New Zealand White rabbits were fed either a cholesterol-free casein diet (CAS; n=10); low-level cholesterol-supplemented (0.125% to 0.5% by weight) chow (CH; n=10); or standard laboratory rabbit chow (n=3) for 24 weeks, during which total plasma cholesterol (TPC) levels were matched for the two experimental groups (TPCCAS=475±39 mg/dL; TPCCH=515±70 mg/dL). The percentage of cholesterol partitioned into each of the lipoprotein fractions except high-density lipoprotein (HDL) was significantly different for the experimental groups: casein-fed rabbits had a primarily low-density lipoprotein (LDL) hypercholesterolemia while cholesterol-fed rabbits had approximately equal levels of very-low-density lipoprotein (VLDL), intermediate-density lipoprotein (IDL), and LDL cholesterol. Despite matched TPC, lesions in CH animals covered twice the luminal surface area (as detected by oil red O staining; P