Tissue-specific alterations in lipoprotein lipase activity in copper-deficient rats

Copper deficiency results in alterations in lipid metabolism that include e levations in serum cholesterol and triglycerides and a decrease in whole-bo dy respiratory quotient. Copper-deficient animals are also leaner even thou gh electron micrographs of the myocardium present increased lipid droplet a ccumulation. To address whether a compromised copper status impacts triglyc eride deposition in a tissue-specific manner, the activity of lipoprotein l ipase was measured in adipose tissue and cardiac and skeletal muscle. Weanl ing rats fed a copper-restricted diet (<1 ppm) for 6 wk demonstrated a grea ter than twofold increase in cardiac lipoprotein lipase activity concomitan t with a significant reduction in adipose tissue lipoprotein lipase activit y. Skeletal muscle lipoprotein lipase activity was not altered by the coppe r-deficient state. The results of this study suggest that copper deficiency may induce a tissue-specific alteration in lipoprotein lipase activity in rats, which may contribute to the notable deposition of lipid substance in myocardium and the concomitant general body leanness.