Ectopic bone formation and aging

Abstract

Six-week-old, 6-month-old, and 2-year-old female rats of the Wistar strain were implanted with decalcified bone powder prepared from rats of the same strain. An encapsulated deposit of cartilage and bone formed. The deposits were removed at intervals and studied histologically and after administration of 45Ca. Intramembranous bone formed in 14 days in the 6-week-old animals, but was not seen until the 23rd day in the 2-year-old rats. This implant system may provide a model for the study of the mechanisms for the decline of osteogenesis, or the low bone formation rate which occurs with aging.