Osteopoietin—Humoral Induction Factor in Osteogenesis

A heat‐stable, glycoprotein‐like material, osteopoietin, produced during bone marrow regeneration, has been shown to induce bone formation when implanted in the rat eye. The material was separated by ultrasonic treatment or by acid buffer (pH 3–5) from sponges implanted in the marrow. The extracted material free of bone or cell solids, induced bone formation in the anterior eye chamber of the rat, whereas the cell solids and control sponges similarly implanted did not.