[Changes in the osteoinductive activity of the bone matrix in ontogeny]

Correlation between the animal's age, degree of mineralization of its bone tissue and the osteoinductive activity of the bone organic matrix was established in experiments with rats of the same litter at an age of 2, 4, 8, 16 weeks. The osteoinductive activity was estimated by the capacity of matrix to induce ectopic osteogenesis using biochemical methods. Bone mineralization increased and the capacity for osteoinduction decreased roughly 1,5-fold with the age of donor animals. It is suggested that the reduction of osteoinductive potencies is based on the decrease in lability of the bond between the protein osteoinducer and the collagen matrix, as shown by unequal sensitivity of bone matrix of rats of different age to the doubling of the shortest possible time of bone demineralization.