Ultrastructure of the effects of calcitonin on the development of mouse tooth germs in vitro.
Mandibular first molars, from 17-day-old embryos, were cultivated in control medium or medium containing 0.1, 0.01 or 0.001 unit/ml of calcitonin (CT) for periods up to 10 days. In untreated tooth germs, cells of the dental papilla differentiated into pre-odontoblasts up to 4 days and predentine was seen on day 6. Cells treated with 0.1 unit/ml of CT differentiated into pre-odontoblasts up to 4 days, but no predentine was formed even after 10 days in culture. With 0.01 unit/ml, cells differentiated into odontoblasts, and had already secreted predentine a few days earlier than the untreated group. With 0.001 unit/ml, the developing germs were similar to the control explants during the entire 10-day cultivation period. The proportional area of rough endoplasmic reticulum to cytoplasm of the odontoblasts was low at 0.1 unit/ml of CT and high at 0.01 unit/ml compared to the untreated explants.
D000818:Animals; D002116:Calcitonin / Q000494:pharmacology*; D003771:Dental Papilla / Q000648:ultrastructure; D004721:Endoplasmic Reticulum / Q000648:ultrastructure; D051379:Mice; D008807:Mice, Inbred BALB C; D008854:Microscopy, Electron; D008963:Molar; D009804:Odontoblasts / Q000648:ultrastructure; D014083:Tooth Germ / Q000187:drug effects* / Q000196:embryology / Q000648:ultrastructure
D002116:Calcitonin