Biomaterial Database

Autoradiographic evaluation of circadian periodicity in cell proliferation in the periodontal ligament of the young mouse. 1987

I J Singh, and H S Sandhu, and E A Tonna

New York University Dental Center, NY 10010.

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.

UI	MeSH Term	Description	Entries
D008297	Male		Males
D008815	Mice, Inbred Strains	Genetically identical individuals developed from brother and sister matings which have been carried out for twenty or more generations, or by parent x offspring matings carried out with certain restrictions. All animals within an inbred strain trace back to a common ancestor in the twentieth generation.	Inbred Mouse Strains,Inbred Strain of Mice,Inbred Strain of Mouse,Inbred Strains of Mice,Mouse, Inbred Strain,Inbred Mouse Strain,Mouse Inbred Strain,Mouse Inbred Strains,Mouse Strain, Inbred,Mouse Strains, Inbred,Strain, Inbred Mouse,Strains, Inbred Mouse
D010513	Periodontal Ligament	The fibrous CONNECTIVE TISSUE surrounding the TOOTH ROOT, separating it from and attaching it to the alveolar bone (ALVEOLAR PROCESS).	Alveolodental Ligament,Alveolodental Membrane,Gomphosis,Alveolodental Ligaments,Alveolodental Membranes,Gomphoses,Ligament, Alveolodental,Ligament, Periodontal,Membrane, Alveolodental,Periodontal Ligaments
D002455	Cell Division	The fission of a CELL. It includes CYTOKINESIS, when the CYTOPLASM of a cell is divided, and CELL NUCLEUS DIVISION.	M Phase,Cell Division Phase,Cell Divisions,Division Phase, Cell,Division, Cell,Divisions, Cell,M Phases,Phase, Cell Division,Phase, M,Phases, M
D002940	Circadian Rhythm	The regular recurrence, in cycles of about 24 hours, of biological processes or activities, such as sensitivity to drugs or environmental and physiological stimuli.	Diurnal Rhythm,Nyctohemeral Rhythm,Twenty-Four Hour Rhythm,Nycthemeral Rhythm,Circadian Rhythms,Diurnal Rhythms,Nycthemeral Rhythms,Nyctohemeral Rhythms,Rhythm, Circadian,Rhythm, Diurnal,Rhythm, Nycthemeral,Rhythm, Nyctohemeral,Rhythm, Twenty-Four Hour,Rhythms, Circadian,Rhythms, Diurnal,Rhythms, Nycthemeral,Rhythms, Nyctohemeral,Rhythms, Twenty-Four Hour,Twenty Four Hour Rhythm,Twenty-Four Hour Rhythms
D000818	Animals	Unicellular or multicellular, heterotrophic organisms, that have sensation and the power of voluntary movement. Under the older five kingdom paradigm, Animalia was one of the kingdoms. Under the modern three domain model, Animalia represents one of the many groups in the domain EUKARYOTA.	Animal,Metazoa,Animalia
D001345	Autoradiography	The making of a radiograph of an object or tissue by recording on a photographic plate the radiation emitted by radioactive material within the object. (Dorland, 27th ed)	Radioautography
D051379	Mice	The common name for the genus Mus.	Mice, House,Mus,Mus musculus,Mice, Laboratory,Mouse,Mouse, House,Mouse, Laboratory,Mouse, Swiss,Mus domesticus,Mus musculus domesticus,Swiss Mice,House Mice,House Mouse,Laboratory Mice,Laboratory Mouse,Mice, Swiss,Swiss Mouse,domesticus, Mus musculus