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Continuous labelling of the periodontal ligament of mice
Author(s) -
McCulloch C. A. G.,
Melcher A. H.
Publication year - 1983
Publication title -
journal of periodontal research
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.31
H-Index - 83
eISSN - 1600-0765
pISSN - 0022-3484
DOI - 10.1111/j.1600-0765.1983.tb00357.x
Subject(s) - labelling , periodontal fiber , cell division , fraction (chemistry) , cell , biology , chemistry , andrology , biochemistry , dentistry , chromatography , medicine
The growth fraction in the mouse periodontal ligament (PL) was determined by means of continuous labelling for up to 60 days with 3 H‐Tdr via the drinking water. The method was tested by comparing the labelling indices (LI) of PL cells obtained in this way with those obtained by repeated injections or via osmotic mini‐pumps. There was no significant difference between the LI obtained by the 3 different routes. Cell density was assayed in the PL of mice who had received no 3 H‐Tdr or that were labelled for 60 days with 3 H‐Tdr. There were no detectable differences in cell density, and we concluded that 3 H‐Tdr cytocide did not significantly change the growth fraction. The growth fraction of PL cells was 30%, and 25 days of continuous labelling were required to obtain this value. No significant change of LI was observed between 25 and 60 days of labelling. This plateau could not be accounted for by loss of PL cells to bone as osteocytes because very few labelled osteocytes were observed, even after 25 days of continuous labelling. The growth fraction of cells within 10 μm of blood vessels was 40% and was significantly higher than the overall growth fraction. These data suggest that cell division in the PL occurs predominantly in a paravascular location and that some of the progeny of dividing cells in the PL die.