Cartilage-perichondrium Interactions Regulate Angiogenesis during Long Bonedevelopment

Introduction. Angiogenesis mediates a pivotal event during endochondral ossification, when blood vessels grow into hypertrophic cartilage and initiate the degradation of its matrix and the migration of bone cells. In this study we examined the molecular and cellular mechanisms regulating angiogenesis during endochondral ossification, with a particular focus on the tissue interactions between perichondrium and cartilage that affect this process. Because of the inherent difficulty in studying the role of one tissue (perichondrium) in the presence of another (cartilage), we developed an ex-vivo approach in order to separate the roles of these two tissues during angiogenic invasion of embryonic cartilage.