Effect of Copper Deficiency on Chick Bone Collagen and Selected Bone Enzymes

Abstract

Studies were conducted with chicks to determine the effect of copper deprivation on collagen formation, mineral content and activity of selected enzymes in bone tissue. After 7 to 10 days on copper-deficient diets, collagen extracted from copper-deficient chick bone contained less aldehyde and was more easily solubilized than collagen from control bone. Collagens were extracted with acetic acid, guanidine·HCl, NaCl and alkali. In all cases, copper-deficient bones yielded greater amounts of soluble collagen. Bone enzyme studies indicated that amine oxidase activity was reduced 30 to 40% in deficient chicks as compared with controls. In the enzyme assays for amine oxidase the in vitro addition of copper resulted in an elevation of activity to that of controls. Bone cytochrome oxidase was also markedly reduced with copper deficiency. The copper-containing enzymes in bone appear to be similar to those reported in other tissues. Catalase was not affected by the deficiency. Bone mineral analyses demonstrated that the calcium, phosphorus and magnesium content of bone ash was normal in both experimental groups. The copper content of control bone was twice that of deficient bone. Extraction of mineral from bone of both copper-deficient and control chicks removed over 96% of the bone mineral, but much of the bone copper was not extracted and appeared to be tenaciously bound to the organic phase of bone.