HIGH-DENSITY LIPOPROTEIN METABOLISM IN NORMOLIPIDEMIC AND CHOLESTEROL-FED RABBITS

New Zealand white rabbits were used to determine the compositional and metabolic changes induced in high density lipoproteins (HDL, ρ = 1.063-1.21 g/ml) in response to cholesterol feeding. There was no change in total HDL cholesterol in plasma due to cholesterol feeding (12 weeks), but the triglyceride level was decreased to 29% of pretreatment values. Total protein content of HDL was decreased in response to cholesterol feeding, resulting in a significant increase in the cholesterol/protein ratio. There was a decrease in some isomer of the major apolipoproteins (A-I2) of HDL. The decay of radioactivity in HDL or its apolipoproteins was biphasic in both normolipidemic and hypercholes-terolemic rabbits. The first phase was much more rapid than the second. The decay rates for the radioactivity in HDL depended upon the dietary status of the recipient animal. © 1978.