A radioautographic study of chondrocytic proliferation in nasal septal cartilage of the newborn rat.

Growth sites within the newborn cartilaginous nasal septum have been identified by monitoring chondrocytic proliferation radioautographically. Tritiated thymidine was the labeling agent used. The results were tabulated and charted graphically; they showed the overall septum to be relatively active mitotically, yielding an average of 3.54 labeled cells per microscopic field counted. However, certain areas showed greater activity than others, namely the anterior tip (4.51 labeled cells/field), the midportion (3.98 labeled cells/field) and the posterior section of the presphenoidal tail (4.24 labeled cells/field).