[Fe and Cu content in bones, muscles and whole body of growing rats with different Fe and Cu supplies].

The Fe and Cu contents in the femur and in the skeleton muscle were investigated in a trial series with factorial Fe and Cu supplies of growing rats (0, 25, 250, and 625 micrograms of Fe supply; 0, 10, 100, and 250 micrograms Cu supply per g of the diet). In addition, the reaction of the carcass to the different trace element supply was compared to the changes of the Fe and Cu contents in organs and tissues. In the femur, the Fe contents clearly increase in all grades of the Cu supply with increasing Fe supply. But because of the reduced live weight of the trial animals without Fe supply, this is valid only from 25 micrograms Fe/g diet on. For all Fe levels, the influence of the Cu supply on the concentration and the content of Cu results in a plateau in the range of 10-100 micrograms Cu/g diet; it is not reached with Cu deficiency and exceeded with an excessive Cu supply (250 micrograms/g). A clear increase of the Fe concentration in the muscle occurs only at a supply of 250 micrograms Fe/g diet. A further increase at 625 micrograms Fe/g only occurs at a Cu supply of 250 micrograms/g. Generally, the Fe concentration is reduced in the Cu deficiency. The Cu concentration in the muscle increases in all cases with the Cu supply, and the extent of this increase is strongly influenced by the Fe supply. The Fe contents in the carcass primarily depend on the Fe dosage. For the total contents of copper there are hints of a homeostatical regulation in the range of 10-100 micrograms Cu/g, but it seems to be disturbed if the Fe supply (0 or 25 micrograms/g) is insufficient. The comparison of the Fe and Cu contents in organs and tissues to those in the carcass shows that the reactions to the different supply levels, which are clearly different in the tissues, can be reproduced but insufficiently by the trace element analysis in the carcass.