title: Autoradiography of protein turnover in subcrestal versus supracrestal fibre tracts of the developing mouse periodontium.
abstract: Eighteen-day-old C57Bl mice were injected with 5 muCi/g body weight [3H]-proline and killed at intervals of 4 h to 7 wk later. Grain counts in three fibre tracts revealed that (1) half-lives of labelled protein in the developing periodontium were much shorter than those found previously for the mature periodontium , and (2) the half-life of labelled protein in the dento-gingival region was longer than the half-lives in the trans-septal and dento-alveolar fibre tracts (half-lives: dento-alveolar = 2.5 days, trans-septal = 3.8 days; dento-gingival = 7.9 days). Eight mice were given injections of [3H]-proline on days 11, 13, 15 and 17, which encompasses the formation of the three fibre tracts, and killed 4 h, 2.5, 5 and 8 wk after the last injection. All label incorporated during the formation of the periodontium had been lost by 5 wk post-injection, showing that a stable core fibre (i.e. one which is not metabolized) was not present.
mesh_terms: D000818:Animals; D001345:Autoradiography; D003094:Collagen / Q000378:metabolism*; D051379:Mice; D008810:Mice, Inbred C57BL; D010519:Periodontium / Q000254:growth & development / Q000378:metabolism*
chemical_list: D003094:Collagen