Croswell, Susan Corrine Effect of Copper Deficiency on the Apolipoprotein-e-rich High Density Lipoprotein Fraction in Rats

Twenty-four male weanling rats were randomly divided into two treatment groups, namely a copper-adequate (8 mg Cu/kg diet) or a copper-deficient (0.85 mg Cu/kg diet) group. Feed and distilled, deionized water were provided ad libitum. After 7 weeks, plasma lipid, protein and apolipoprotein concentrations of high density lipoproteins (HDL) and subfractions of HDL were determined. Significant elevations in the protein and cholesterol contents of HDL and the second retained (RLL) subfraction of HDL were observed in the copper deficient rats. In addition, the apolipoprotein E (apo-E) concentration of HDL and the RJJ subfraction of HDL was significantly increased due to copper deficiency. Copper deficiency also significantly elevated the level of apolipoprotein AI (apo-AI) of the RJJ subfraction. Data obtained in this study suggest that the hypercholesterolemia associated with copper deficiency was due to an impairment in the cholesterol degradation process regardless of an increase in the apo-E-rich HDL fraction.