title: Validation of a liquid chromatography-mass spectrometry method to assess the metabolism of dextromethorphan in rat everted gut sacs.
abstract: A rapid, sensitive and selective liquid chromatography-mass spectrometry (LC-MS) method was developed for the simultaneous assay of dextromethorphan and its metabolites in tissue culture medium and its intestinal metabolism studied with the rat everted gut sac model. The method was validated in the concentration range of 0.1-2.5 microM (27.1 ng/mL-0.677 microg/mL) for dextromethorphan and 0.005-0.5 microM for dextrorphan and 3-methoxymorphinan (1.28 ng/mL-0.128 microg/mL) and 3-hydroxymorphinan (1.22 ng/mL-0.122 microg/mL). The limits of quantification (LOQ) were 0.0025 microM (12.5 fmoles, 3.4 pg, 5 microL injected) for dextromethorphan; 0.0025 microM for dextrorphan, 3-methoxymorphinan (24.9 fmoles, 6.4 pg injected), and 3-hydroxymorphinan (25.1 fmoles, 6.1 pg injected) with 10 microL injected. The detection of dextrorphan and 3-methoxymorphinan showed that both the P450 isoforms CYP3A and 2D were active in the intestinal mucosa and metabolised dextromethorphan during its passage across the mucosa.
authors.affiliation: Laboratoire de Cinétique des Xénobiotiques, UMR 181, Physiopathologie et Toxicologie Experimentale (UPTE INRA-ENVT), Faculté des Sciences Pharmaceutiques, 35 Chemin des Maraîchers, 31062 Toulouse, France. arellano@cict.fr
authors.forename: C
authors.initials: C
authors.lastname: Arellano
authors.forename: C
authors.initials: C
authors.lastname: Philibert
authors.forename: E N
authors.initials: EN
authors.lastname: Dane à Yakan
authors.forename: C
authors.initials: C
authors.lastname: Vachoux
authors.forename: O
authors.initials: O
authors.lastname: Lacombe
authors.forename: J
authors.initials: J
authors.lastname: Woodley
authors.forename: G
authors.initials: G
authors.lastname: Houin
mesh_terms: D000818:Animals; D001189:Aryl Hydrocarbon Hydroxylases / Q000378:metabolism; D002853:Chromatography, Liquid / Q000379:methods*; D019389:Cytochrome P-450 CYP2D6 / Q000378:metabolism; D051544:Cytochrome P-450 CYP3A; D003915:Dextromethorphan / Q000031:analogs & derivatives* / Q000032:analysis* / Q000378:metabolism*; D003917:Dextrorphan / Q000032:analysis / Q000378:metabolism; D066298:In Vitro Techniques; D007413:Intestinal Mucosa / Q000201:enzymology; D007421:Intestine, Small / Q000378:metabolism*; D008297:Male; D013058:Mass Spectrometry / Q000379:methods*; D010089:Oxidoreductases, N-Demethylating / Q000378:metabolism; D051381:Rats; D017207:Rats, Sprague-Dawley; D015203:Reproducibility of Results; D012680:Sensitivity and Specificity
chemical_list: D003917:Dextrorphan; C028657:3-methoxymorphinan; D003915:Dextromethorphan; D001189:Aryl Hydrocarbon Hydroxylases; D019389:Cytochrome P-450 CYP2D6; D051544:Cytochrome P-450 CYP3A; D010089:Oxidoreductases, N-Demethylating; C054116:norlevorphanol