Autoradiographic evaluation of circadian periodicity in cell proliferation in the periodontal ligament of the young mouse
Five-week-old BNL male mice were maintained on a 12-h light/dark cycle, subcutaneously injected with [ 3H]-thymidine 1 h before death and killed every 3 h for 24 h. Autoradiographs were made from demineralized, paraffin-wax embedded sagittal sections of maxillae. The labelling index was calculated f...
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Published in | Archives of oral biology Vol. 32; no. 5; pp. 377 - 379 |
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Main Authors | , , |
Format | Journal Article |
Language | English |
Published |
England
Elsevier Ltd
1987
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Subjects | |
Online Access | Get full text |
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Summary: | Five-week-old BNL male mice were maintained on a 12-h light/dark cycle, subcutaneously injected with [
3H]-thymidine 1 h before death and killed every 3 h for 24 h. Autoradiographs were made from demineralized, paraffin-wax embedded sagittal sections of maxillae. The labelling index was calculated for fibroblast-like cells of the periodontal ligament mesial to the first molar. A bimodal distribution of labelled cells was seen. Labelling index was highest at 0900 h (light period); a second, lower, peak was seen at 2400 h (dark period). Cell proliferation was significantly increased during the light period. The increased activity during the dark period may represent a superimposed secondary, ultradian, rhythm, differences in periodontal cell subtypes or may be related to the feeding and activity cycle of the mouse. Thus there is a 24-h cyclic rhythmicity in the proliferation of periodontal-ligament cells in the mouse. |
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Bibliography: | ObjectType-Article-1 SourceType-Scholarly Journals-1 ObjectType-Feature-2 content type line 23 |
ISSN: | 0003-9969 1879-1506 |
DOI: | 10.1016/0003-9969(87)90095-1 |