PMID: 708351Oct 1, 1978Paper

Effects of fracture trauma, estrone treatment, and 2-G environment on the epiphyseal cartilage zones of developing avian radii

Aviation, Space, and Environmental Medicine
J A Negulesco


Female birds subjected to closed fracture of the right radius at 2 weeks post-hatching were allowed to heal for 14 d at either earth gravity (1 G) or a 2-G hypergravity state, with saline-injected controls and 0.2- and 0.4-mg estrone (estrogen) treated groups. Animals were sacrificed following the last injection and radii were routinely processed histologically for micrometer measurements of the mid-coronal height and width of the cartilage zones of the proximal and distal epiphyses. Proximal epiphyses of estrone-treated, normo-gravity chicks showed a decreased growth in height of the articular, proliferating, and hypertrophic cartilage zones and an increased interstitial growth of the hypertrophic and calcified layers of estrone-treated, 2-G animals. Growth in height of the cartilage layers of the distal epiphyses of fractured radii was primarily stimulated when estrone-treated chicks were also exposed to the 2-G state. Appositional growth of all cartilage layers of the proximal and distal epiphyses of normo-gravity birds was increased by 0.2 mg estrone. In addition, growth in the width of all cartilage layers of the distal epiphyses of 2-G animals was increased with the administration of 0.4 mg estrone.

Related Concepts

Epiphysis of Bone
Radius Fractures

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