title: Effects of actinomycin D on developing hamster molar tooth germs in vitro.
abstract: The aim of this study was to evaluate the toxic effects of actinomycin D on the developing hamster tooth germ in organ culture. Hamster tooth germs during early secretory amelogenesis were exposed in vitro for 24 h to 10(-9) M-5 x 10(-5) M actinomycin D. Actinomycin D dose-dependently (> or = 10(-7) M) decreased the tooth germ dry weight but mineralization was affected only by doses > or = 10(-5) M. However, the uptakes of TCA-insoluble 32P and [3H]thymidine were significantly reduced dose-dependently from > or = 10(-8) M actinomycin D, indicating that the drug inhibits the synthesis of phosphate-containing macromolecules as well as DNA synthesis. Histologically, 10(-8) M actinomycin D was the lowest dose which was not toxic to any cell type in the developing tooth germ. At 10(-7) M actinomycin D, the most sensitive cells were the proliferating pre-odontoblasts followed by pre-ameloblasts; the mature secretory ameloblasts and odontoblasts appeared unaffected. Higher doses resulted in increased cytotoxicity to the secretory cells and, eventually, total degeneration of most cells. The data suggest that children treated for cancer during tooth development using anti-chemotherapy cocktails containing actinomycin D (serum levels > 10(-7) M) may develop defects later on in the mature dentition as a direct consequence of the toxicity of the drug to the tooth organ.
authors.affiliation: Dept. Oral Cell Biol., ACTA-Vrije Universiteit, Amsterdam, The Netherlands. DM.Lyaruu.OCB.ACTA@Med.VU.NL
authors.forename: D M
authors.initials: DM
authors.lastname: Lyaruu
authors.forename: M A
authors.initials: MA
authors.lastname: van Duin
authors.forename: T J
authors.initials: TJ
authors.lastname: Bervoets
authors.forename: J H
authors.initials: JH
authors.lastname: Wöltgens
authors.forename: A L
authors.initials: AL
authors.lastname: Bronckers
mesh_terms: D000565:Ameloblasts / Q000187:drug effects; D000566:Amelogenesis / Q000187:drug effects; D000818:Animals; D000903:Antibiotics, Antineoplastic / Q000008:administration & dosage / Q000009:adverse effects*; D002118:Calcium / Q000378:metabolism; D002132:Calcium Radioisotopes; D002455:Cell Division / Q000187:drug effects; D006224:Cricetinae; D004247:DNA / Q000096:biosynthesis / Q000187:drug effects; D003609:Dactinomycin / Q000008:administration & dosage / Q000009:adverse effects*; D003743:Dental Enamel / Q000187:drug effects; D004305:Dose-Response Relationship, Drug; D008963:Molar; D009804:Odontoblasts / Q000187:drug effects; D009805:Odontogenesis / Q000187:drug effects; D009924:Organ Culture Techniques; D009929:Organ Size; D010758:Phosphorus / Q000378:metabolism; D010761:Phosphorus Radioisotopes; D012995:Solubility; D013936:Thymidine / Q000378:metabolism; D014074:Tooth Calcification / Q000187:drug effects; D014083:Tooth Germ / Q000166:cytology / Q000187:drug effects*; D014238:Trichloroacetic Acid; D014316:Tritium
chemical_list: D000903:Antibiotics, Antineoplastic; D002132:Calcium Radioisotopes; D010761:Phosphorus Radioisotopes; D014316:Tritium; D003609:Dactinomycin; D010758:Phosphorus; D014238:Trichloroacetic Acid; D004247:DNA; D002118:Calcium; D013936:Thymidine