Impaired mechanical strength of bone in experimental copper deficiency.
Copper, through its role as cofactor for lysyl oxidase, is essential for intra- and inter-molecular cross-links in collagen. Copper deficiency, in man and in animals, is associated with bone fragility ascribed to defective cross-links. To assess bone strength in copper-deficient animals, we designed a sensitive torsion-testing apparatus according to biomechanical considerations. Femora from 7 copper-deficient rats and from their pair-fed controls were tested in torsional loading until fracture. Significant decreases in the maximal sustained torque (t = 2.93, p < 0.05), in the ultimate angular deformation (t = 2.52, p < 0.05) and in the toughness (t = 2.88, p < 0.05) were demonstrated. In a complementary study, it was shown that the ash weight and the calcium content of the femora from the copper-deficient animals did not differ from those of the controls. It was likely, therefore, that the impaired mechanical strength was related to defects in the collagen component of bone.
Jonas
J
J
School of Biomedical Engineering, University of Dundee, UK.
Burns
J
J
Abel
E W
EW
Cresswell
M J
MJ
Strain
J J
JJ
Paterson
C R
CR
D000818:Animals; D001696:Biomechanical Phenomena; D001842:Bone and Bones / Q000737:chemistry / Q000502:physiology; D002118:Calcium / Q000032:analysis; D003094:Collagen / Q000032:analysis; D003300:Copper / Q000172:deficiency* / Q000378:metabolism; D004195:Disease Models, Animal; D005269:Femur / Q000737:chemistry / Q000502:physiology*; D050723:Fractures, Bone; D008099:Liver / Q000737:chemistry; D051381:Rats; D017208:Rats, Wistar; D014102:Torsion Abnormality
D003300:Copper; D003094:Collagen; D002118:Calcium