Lipoproteins and liver lipids in copper-deficient rats

Abstract

The influence of dietary copper deficiency on plasma lipoproteins and liver lipids was examined in rats using cholesterol free, semi-purified diets in two separate experiments. In Experiment 1, copper deficiency was associated with a 91% elevation in plasma cholesterol and a 13% decrease in HDL cholesterol. The normal HDL/(VLDL+LDL) cholesterol ratio of 2:1 in copper-adequate rats was essentially reversed by copper deficiency. Aortic cholesterol concentration was increased by 15% in copper-deficient rats. In Experiment 2 copper deficiency produced very similar changes in plasma lipoproteins as observed in Experiment 1. In addition, copper deficiency was associated with an increase in HDL free cholesterol, a decrease in HDL cholesteryl esters, a marked increase in (VLDL+LDL) cholesteryl esters with a smaller increase in free cholesterol of (VLDL+LDL). Copper deficiency was associated with a decrease in liver cholesteryl ester concentrations, but no changes in liver free cholesterol. Liver triglycerides were also decreased by copper deficiency and plasma triglycerides were markedly increased. Possible effects of dietary copper deficiency on lipoprotein and cholesterol metabolism are discussed.