title: Effect of phenytoin on intracellular 45Ca2+ accumulation in gingival fibroblasts in vitro.
abstract: Effect of 5,5 diphenylhydantoin (phenytoin; PHT) alone or in combination with epidermal growth factor (EGF) on the intracellular accumulation of the radioisotope 45Ca2+ (4 min labelling period) was determined in gingival fibroblasts. EGF as well as PHT increased the intracellular accumulation of the radioisotope in normal gingival fibroblasts by approximately 2 and 1.6-fold, respectively. In contrast, in fibroblasts derived from the phenytoin-induced gingival overgrowth, neither EGF nor PHT stimulated intracellular accumulation of 45Ca2+. When normal gingival fibroblasts were treated in vitro with EGF in combination with PHT, the EGF-induced increase in intracellular accumulation of the radioisotope 45Ca2+ was abolished. The rate of efflux of the radioisotope 45Ca2+ in prelabelled normal gingival fibroblasts was decreased by PHT treatment in vitro to a level already present in fibroblasts derived from PHT-induced gingival overgrowth. This study indicates that PHT influences the cellular calcium metabolism in fibroblasts which may contribute to the pathogenesis of gingival overgrowth.
authors.affiliation: Department of Pedodontics, Faculty of Odontology, Karolinska Institute, Huddinge, Sweden.
authors.forename: G
authors.initials: G
authors.lastname: Brunius
authors.forename: T
authors.initials: T
authors.lastname: Modéer
mesh_terms: D000293:Adolescent; D002118:Calcium / Q000493:pharmacokinetics*; D002132:Calcium Radioisotopes; D002478:Cells, Cultured; D002648:Child; D004815:Epidermal Growth Factor / Q000008:administration & dosage / Q000494:pharmacology*; D005347:Fibroblasts / Q000378:metabolism*; D005881:Gingiva / Q000166:cytology* / Q000378:metabolism; D005885:Gingival Hyperplasia / Q000378:metabolism / Q000473:pathology*; D006801:Humans; D010672:Phenytoin / Q000008:administration & dosage / Q000494:pharmacology*; D013997:Time Factors
chemical_list: D002132:Calcium Radioisotopes; D010672:Phenytoin; D004815:Epidermal Growth Factor; D002118:Calcium