CELL POPULATION KINETICS OF AN OSTEOGENIC TISSUE. II.
A study of the cell kinetics on the actively growing periosteal surface of the femur of rabbits aged 2 weeks has been continued. A single injection of tritiated thymidine was given and the rabbits killed from 1 hour to 4 days after injection. The grain count spectra of the different cell types, pre-osteoblast, osteoblast, and osteocyte, have been compared at different times after injection. The results showed evidence for the uptake of thymidine in nuclei which is not associated with cell division. A small percentage of osteoblasts was initially labeled at 1 hour and there was evidence that the majority of these had not divided by 3 or 4 days after injection. Some thymidine-labeled cells had also become osteocytes without division. Furthermore, it appeared that a considerable fraction of the initially labeled pre-osteoblasts did not divide. The S period for the pre-osteoblasts and osteoblasts was measured using a double-labeled thymidine technique.
D000818:Animals; D001345:Autoradiography; D002455:Cell Division; D002467:Cell Nucleus; D005269:Femur; D006801:Humans; D007700:Kinetics; D010006:Osteoblasts; D010521:Periosteum; D011817:Rabbits; D012106:Research; D013936:Thymidine; D014316:Tritium
D014316:Tritium; D013936:Thymidine
CELL DIVISION; EXPERIMENTAL LAB STUDY; PERIOSTEUM; RABBITS; RADIOAUTOGRAPHY; THYMIDINE; TRITIUM