The distribution of osteocalcin, degree of mineralization, and mechanical properties along the length of Cyprinus carpio rib bone

This study examined the spatial distribution of selected biochemical and mechanical properties along the length of carp rib bone. Carp rib bone was chosen because of its unusually high osteocalcin content relative to other extractable proteins. The amount of osteocalcin was significantly lower (p <0.01) at the most distal section, relative to all other sections. The amount of phosphate (p <0.05) and the elastic modulus in the longitudinal plane (p <0.0001) were found to be significantly higher in the most distal section, relative to the most proximal section. There was no significant difference in the calcium distribution, molar Ca/P ratio, or elastic modulus in the transverse plane. It was speculated that the distal section contains less mature bone. The methods illustrate the potential usefulness of nanoindentation to characterize the mechanical properties of bone, relative to its biochemical composition. (C) 2001 Kluwer Academic Publishers.