The expression of collagen mRNAs in normally developing neonatal rabbit long bones and after treatment of neonatal and adult rabbit tibiae with transforming growth factor-β2

摘要: Normal transverse growth of long bones is by periosteal appositional bone formation, balanced endosteal resorption. Changes in the distribution cells that are expressing collagen mRNAs during were determined using digoxigeninlabelled riboprobes. In neonatal rabbit tibiae osteoblasts type I mRNA found on periosteal, and at early stages endosteal, surfaces lining peripheral cavities. Occasional osteocytes express very weakly. The pattern disrupted when transforming factor-β2 (TGF-β2) injected daily into periosteum animals; there increased bone, later cartilage, formation. Three injections 20 ng TGF-β2 onto tibia 3-day-old rabbits led to an increase for collagen. Some newly-formed woven also mRNA. After five chondrocytes II around injection site. Similar old induce only fibrous tissue within which some This precise localization shows expression or here restricted chondrocytes, respectively.