AJP - Renal Physiology, Vol 232, Issue 4 358-F363, Copyright © 1977 by American Physiological Society
Autoradiography of the water compartments in developing teeth of young mice
G. E. Lyman and W. J. Waddell
The distribution of [14C-a1acetyl-4-aminoantipyrine ([14C]NAAP), as
indicators of total tissue water, and [carboxy-14C]inulin ([14C]inulin), as
an indicator of extracellular water, were studied by autography in mice
4-16 days old. An autographic technique was used that does not translocate
or remove the radioactive material. Photometric densities of the
autoradiographs revealed wide variations in radioactivity among the various
areas of the teeth. Evidence for binding of [14C]urea to bone limits the
usefulness of this compound as an indicator. Although [14C]inulin appeared
to be a reliable indicator, it is difficult to correlate its distribution
with the progress of mineralization determined by electron microprobe
analysis. [14C]NAAP was considered to be the most reliable indicator; it
revealed that the water content of various areas of the teeth ranged from 7
to 100% of that in blood.
