Effect of mechanical loading on insulin-like growth factor-I gene expression in rat tibia

摘要: Mechanical loading plays an essential role in maintaining skeletal integrity. stimulation leads to increased bone formation. However, the cellular and molecular mechanisms that are involved translation of mechanical stimuli into formation, not completely understood. Growth factors osteocytes, which act as mechanosensors, play a key during formation after stimulation. The aim this study was characterize IGF-I locally rat tibiae. Fifteen female Wistar rats were randomly assigned three groups (nZ5): load, sham-loaded, control. fourpoint bending model Forwood Turner used induce single period on tibia shaft. effects mRNA expression determined with non-radioactive situ hybridization decalcified tibiae sections, 6 h session. Endogenous expressed trabecular cortical osteoblasts, some sub-endocortical intracortical endothelial cells blood vessels, periosteum. Megakaryocytes, macrophages, myeloid also mRNA. In growth plate, located proliferative hypertrophic chondrocytes. did affect marrow cells, chondrocytes, but osteocytes at endosteal side shaft showed twofold increase expression. proportion positive loaded 29.3G12.9% (meanGS.D.; nZ5), whereas sham-loaded contra-lateral control exhibited 16.7G4.4% (nZ5) 14.7G4.2% (nZ10) respectively (P!0.05). Lamellar session observed conclusion, results up-regulation synthesis present multiple layers extending mechanically stimulated loading. This supports hypothesis IGF-I, is