Copper status in the rat is affected by modes of copper delivery.

The purpose of this study was to determine whether the interaction between fructose and copper status can be affected by the mode of copper administration. Male Sprague-Dawley rats (n = 94) were fed from weaning diets that contained 0.65-0.85 mg copper/kg diet for 42 d. The experimental design of the study was a 2 x 2 x 3 analysis of variance: two types of carbohydrate (fructose, corn starch), two modes of copper delivery (orally or subcutaneously) and three different extrinsic copper levels (0, 1.5 or 3 mg/kg diet or 0, 11.25 or 22.5 micrograms Cu/d by injection). In the rats fed fructose, direct indicators of copper status such as plasma copper and tissue superoxide dismutase activity were increased to a much greater extent when copper was supplied subcutaneously rather than orally as part of the diet. In the starch-fed rats the effect of the mode of copper delivery on the levels of these indices was usually not significantly different. As a result, the feeding of fructose as compared to starch produced lower levels of direct indicators of copper status when copper was supplied in the diet but not subcutaneously. It appears that ingestion of fructose as compared to starch increases the requirement for copper and that the mode of copper administration that circumvents the gastrointestinal tract attenuates the fructose-copper interaction. Thus, the fructose-copper interaction occurs either during intestinal digestion and absorption, hepatic uptake of copper via the portal blood or its hepatic utilization.