POOL SIZE AND CONCENTRATION OF PLASMA-CHOLESTEROL ARE INCREASED AND TISSUE COPPER LEVELS ARE REDUCED DURING EARLY STAGES OF COPPER DEFICIENCY IN RATS

The progressive development of hypercholesterolemia, enlargement of pl asma cholesterol pool size, and alteration in tissue mineral concentra tions were determined during the early stages of copper deficiency. Fi fty-four weanling male Sprague-Dawley rats were assigned to three diet ary Cu treatments: deficient (0.6 mu g Cu/g diet), marginal (1.6 mu g Cu/g diet) and adequate (6.6 mu g Cu/g diet). Six rats from each treat ment were killed after 3, 5 and 7 wk of dietary treatment. After only 3 wk of treatment, significantly lower hematocrits and liver Cu concen trations, as well as enlargements of plasma volume, plasma pool size o f cholesterol and triacylglycerols and relative heart weight, were evi dent in rats fed the Cu-deficient and Cu-marginal diets relative to th ose fed the Cu-adequate diet. In general, these alterations were more pronounced in rats fed the Cu-deficient diet than in rats fed the Cu-m arginal diet. Thereafter, the hematocrits and plasma volumes remained relatively constant, but the liver Cu concentration progressively decr eased in rats in all treatments throughout the study. In contrast, the enlargements in plasma pool size of cholesterol and triacylglycerols relative to Cu-adequate rats were greater at the end of the study for the Cu-marginal and Cu-deficient rats. Most importantly, in the Cu-mar ginal rats, significantly greater plasma cholesterol and triacylglycer ol pool sizes were detected earlier than were differences in concentra tions. Thus, the present study established plasma cholesterol and tria cylglycerol pool sizes as superior indices for the early detection of alterations in lipid metabolism in Cu deficiency.