Aging-induced osteopenia in avian cortical bone

Cortical bone loss contributes substantially to the degradation of skeletal integrity associated with aging. However, animal models that closely mimic age-related alterations in cortical bone are limited. The objective of thi s study was to determine if aged rooster cortical bone demonstrates phenoty pic alterations similar to those observed in aged human cortical bone (i.e, , expansion of the endocortical and periosteal envelopes and elevated corti cal porosity). When compared with young adult roosters, aged roosters demon strated significant expansion of the endocortical (16%) and periosteal (10% ) envelopes, resulting in significantly increased cross-sectional moments o f inertia. In addition, aged rooster bone demonstrated significantly elevat ed cortical porosity (51%) and average area of porosity (83%). We conclude that rooster bone demonstrates age-related adaptations similar to those of humans at both tissue and cellular levels, and may therefore represent a re latively useful, inexpensive animal model for investigating the mechanisms of age-related bone loss. (Bone 26:361-365; 2000) (C) 2000 by Elsevier Scie nce Inc. All rights reserved.