The pattern of ATP-creatine phosphotransferase activity in growing long bones of new-born mice

Synopsis The localization of creatine kinase (ATP-creatine phosphotransferase) in growing long bones of new-born mice was studied histochemically. Its activity was found to vary within and between different areas of the cartilagenous epiphyses of proximal tibia. Chondrocytes in the cartilaginous epiphysis showed a high cytoplamatic activity. Active enzyme was also apparent within the growth plate of the diaphysis (with the exception of degenerated cells), in the metaphyseal part of the growth plate within the matrix and in neighbouring areas of the metaphysis, and in areas containing lamella bone. Periosteum and perichondrium also showed signs of enzyme activity. The significance of these findings is discussed in relation to the growth process.