Short-term effects of fluoride on biosynthesis of enamel-matrix proteins and dentine collagens and on mineralization during hamster tooth-germ development in organ culture.
The effect of various concentrations of fluoride (F-) on cell proliferation, matrix formation and mineralization was examined in hamster molar tooth germs in premineralizing and mineralizing stages. The exposure lasted 16 h (mineralizing stages) and 24 h (premineralizing stages) and the F- levels ranged from 2.63 microM to 2.63 mM; [3H]-thymidine, [3H]-proline, 45Ca and 32PO4 were used as markers for cell proliferation, matrix formation and mineralization, respectively. The proline-labelled amelogenins were isolated by sequential extraction with water and formic acid and their nature examined by SDS-urea-polyacrylamide electrophoresis. Digestion by collagenase was used to assess the amount of proline incorporated into collagens. F- in concentrations up to 1.31 mM inhibited neither biosynthesis of DNA and amelogenins, nor synthesis of collagens and their hydroxylation. Amelogenins extracted from F- induced, non-mineralizing enamel matrix had the same electrophoretic mobility and the same degree of phosphorylation as amelogenins from normal, mineralizing enamel. However, F- increased the uptake of 45Ca and TCA-soluble 32P dose-dependently, starting with 52 microM. Thus, interference with secretion of enamel matrix by F- takes place at much lower concentrations than required to inhibit biosynthesis of enamel matrix.
D000818:Animals; D002132:Calcium Radioisotopes / Q000378:metabolism; D003094:Collagen / Q000096:biosynthesis*; D006224:Cricetinae; D003746:Dental Enamel Proteins / Q000096:biosynthesis*; D003804:Dentin / Q000187:drug effects*; D004305:Dose-Response Relationship, Drug; D004591:Electrophoresis, Polyacrylamide Gel; D005459:Fluorides / Q000494:pharmacology*; D006900:Hydroxylation; D008647:Mesocricetus; D008903:Minerals / Q000378:metabolism; D009805:Odontogenesis / Q000187:drug effects*; D009924:Organ Culture Techniques; D010761:Phosphorus Radioisotopes / Q000378:metabolism; D011392:Proline / Q000378:metabolism; D014083:Tooth Germ / Q000187:drug effects*
D002132:Calcium Radioisotopes; D003746:Dental Enamel Proteins; D008903:Minerals; D010761:Phosphorus Radioisotopes; D003094:Collagen; D011392:Proline; D005459:Fluorides