Dietary Cellulose, Zinc and Copper: Effects on Tissue Levels of Trace Minerals in the Rat

Abstract

This study was designed to examine the effect of graded levels of cellulose, zinc and copper on tissue mineral levels. Tissue mineral levels were assayed by atomic absorption spectrophotometry in samples collected from a study which involved 12 treatments in a 3 X 2 X 2 factorial arrangement. This study involved three levels of cellulose (0, 8, and 16% of the diet), two levels of Cu (deficient and adequate; 2 and 18 mg/kg of diet, respectively), and two levels of Zn (marginal and abundant; 10 and 120 mg/kg of diet, respectively). Six weanling, male Sprague-Dawley rats were assigned to each treatment and after 9 weeks they were killed. Reductions of tissue Cu content were observed in the serum, liver, tibia and testis of the rats fed the Cu-deficient diets. The Fe content of the tibia and testis was reduced, but that of liver was elevated in the rats fed Cu-deficient diets. Reductions in tibial Zn levels were observed in the rats fed marginal-Zn as compared to those fed the abundant-Zn diets; and in the rats fed Cu-adequate as compared to those fed Cu-deficient diets. Increases in cellulose resulted in increased liver and testicular Cu content only in rats fed the Cu-deficient diets. Additions of cellulose appeared to have no adverse effect on the distribution of Zn, Cu and Fe in tissues which are sensitive to dietary deficiencies. With the exception of rats fed the copper-deficient, marginal zinc diets, the rats fed the other diets demonstrated a small reduction in serum zinc values as cellulose was increased.

Effect of copper supplementation on the copper status of pasture‐fed young Thoroughbreds

“…In cattle, copper supplementation did not increase bone copper concentration, but copper depletion significantly reduced the organic matter content of bones (Suttle and Angus 1978). Copper-depleted rats had increased bone zinc concentration and decreased iron concentration (Tsai and Lei 1979). In the present study, there was no effect of copper supplementation of the mare or foal on bone mineral concentration or bone ash content.…”

Bioavailability of Copper Bound to Dietary Fiber in Mice and Rats

“…Tissues were wet-ashed according to the method of Tsai and Lei (1979). The samples were then diluted to suitable volumes for trace mineral determinations by flame atomic absorption spectrophotometry .…”

“…This bioavailability was determined in both mice and rats to compare the species specificity of the effects of dietary fiber. Two fiber sources, cellulose and wheat bran, were used in this study because cellulose has little affinity for for copper (Tsai and Lei, 1979;Thompson and Weber, 1982;Jiang, 1986) while wheat bran has a high ion exchange capacity and readily binds copper (Thompson and Weber, 1982;Moorman et al, 1983). Bioavailability was assessed by copper status as indicated by body weights, tissue weights, food consumption and tissue contents of copper.…”