title: Sparteine oxidation by the human liver: absence of inhibition by mephenytoin.
abstract: Recent population data suggest independence of the genetic polymorphisms in mephenytoin and sparteine/debrisoquine oxidation. We used human liver preparations to test whether mephenytoin competes with sparteine for binding to the genetically variable cytochrome P-450, which mediates metabolism of both sparteine and debrisoquine. Mephenytoin failed to inhibit in vitro sparteine oxidation. This provides biochemical evidence that the polymorphism of sparteine/debrisoquine metabolism is not related to that of mephenytoin.
mesh_terms: D001667:Binding, Competitive / Q000187:drug effects; D003577:Cytochrome P-450 Enzyme System / Q000378:metabolism; D006801:Humans; D006827:Hydantoins / Q000494:pharmacology*; D066298:In Vitro Techniques; D008099:Liver / Q000187:drug effects / Q000378:metabolism*; D008617:Mephenytoin / Q000494:pharmacology*; D010084:Oxidation-Reduction; D013034:Sparteine / Q000037:antagonists & inhibitors / Q000378:metabolism*
chemical_list: D006827:Hydantoins; D013034:Sparteine; D003577:Cytochrome P-450 Enzyme System; D008617:Mephenytoin