title: Simple method for determination of the active metabolite of the inotropic drug pimobendan in rat liver microsomes.
abstract: A rapid and sensitive high-performance liquid chromatographic method for quantitation of the O-demethylated active metabolite formed in a liver microsomal assay system has been developed. The metabolite was separated on an Inertsil ODS-2 column and quantitated by fluorescence detection (excitation at 338 nm, emission at 405 nm). The retention times for pimobendan and its metabolite were 5.6 and 2.8 min, respectively. The intra- and inter-assay relative standard deviations in the measurement of pimobendan O-demethylase activity at the substrate concentrations of 1 microM and 500 microM were 2.0%, 6.8%, 2.1% and 5.6%, respectively, and the limit of detection was 0.1 ng for the demethylated metabolite.
authors.affiliation: Division of Pharmacy, Chiba University Hospital, Japan.
authors.forename: S
authors.initials: S
authors.lastname: Kuriya
authors.forename: S
authors.initials: S
authors.lastname: Ohmori
authors.forename: M
authors.initials: M
authors.lastname: Hino
authors.forename: C
authors.initials: C
authors.lastname: Senda
authors.forename: K
authors.initials: K
authors.lastname: Sakai
authors.forename: T
authors.initials: T
authors.lastname: Igarashi
authors.forename: M
authors.initials: M
authors.lastname: Kitada
mesh_terms: D000818:Animals; D002138:Calibration; D002316:Cardiotonic Agents / Q000032:analysis / Q000378:metabolism; D002851:Chromatography, High Pressure Liquid / Q000379:methods; D008297:Male; D008862:Microsomes, Liver / Q000378:metabolism*; D011724:Pyridazines / Q000032:analysis* / Q000378:metabolism; D051381:Rats; D017207:Rats, Sprague-Dawley; D015203:Reproducibility of Results
chemical_list: D002316:Cardiotonic Agents; D011724:Pyridazines; C041648:pimobendan