Miniature swine were fed a low (2.7%) fat control stock diet alone or supplemented with either 20% lard plus 1% cholesterol or 20% lard alone for periods of up to 6 months. 2. Cholesterol feeding reduced VLDL fluidity drastically and LDL fluidity minimally but had no effect on HDL fluidity. 3. Lard feeding had no effect on lipoprotein fluidity. 4. The rigid VLDL produced by cholesterol feeding was enriched in cholesterol and phospholipid contents, similar to beta-VLDL. 5. Plasma cholesterol concentrations were increased by 1.5 to 5-fold in pigs fed stock diets supplemented with 20% lard, with or without added cholesterol, but plasma triacylglycerol concentrations were not affected by either diet modification. 6. Diet effects were complete within 4 weeks with no further changes for periods up to 6 months. 7. Regression of the induced hypercholesterolemia was also accomplished within one month of removing cholesterol from the diet.
