Stimulation of miniature end-plate potential frequency by fluoride may involve activation of protein kinase C.
NaF caused a dose-dependent rise in miniature end-plate potential (MEPP) frequency at the frog neuromuscular junction. The effects on MEPP frequency of both NaF and the phorbol ester 12-O-tetradecanoylphorbol-13-acetate (TPA) were rapidly reversed by the protein kinase C (PKC) inhibitor polymyxin B (2 microM). Theophylline augmented the response of MEPP frequency to TPA. It is concluded that the effect of fluoride on MEPP frequency may be through activation of phospholipase C and consequent PKC stimulation, and that the synergistic interaction of NaF and theophylline is consistent with such a mode of action.
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School of Biological Sciences, University of Birmingham, Edgbaston, U.K.
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D000818:Animals; D004075:Diglycerides / Q000096:biosynthesis; D004347:Drug Interactions; D004789:Enzyme Activation; D019204:GTP-Binding Proteins / Q000502:physiology; D066298:In Vitro Techniques; D009045:Motor Endplate / Q000187:drug effects* / Q000502:physiology; D009469:Neuromuscular Junction / Q000187:drug effects / Q000502:physiology; D011112:Polymyxin B / Q000494:pharmacology; D011493:Protein Kinase C / Q000378:metabolism*; D011896:Rana temporaria; D012969:Sodium Fluoride / Q000494:pharmacology*; D013268:Stimulation, Chemical; D013806:Theophylline / Q000494:pharmacology; D010738:Type C Phospholipases / Q000187:drug effects
D004075:Diglycerides; D012969:Sodium Fluoride; D013806:Theophylline; D011493:Protein Kinase C; D010738:Type C Phospholipases; D019204:GTP-Binding Proteins; D011112:Polymyxin B