title: Characterization of midazolam metabolism in locusts: the role of a CYP3A4-like enzyme in the formation of 1'-OH and 4-OH midazolam.
abstract: 1. The metabolism of midazolam was investigated in vivo in locusts in order to evaluate the presence of an enzyme with functionality similar to human CYP3A4/5. 2. Hydroxylated metabolites of midazolam identical to human metabolites were detected in locusts and the apparent affinities (Km values) were in the same range as reported in humans (in locusts: 7-23 and 33-85 µM for the formation of the 1'-OH and 4-OH metabolites, respectively). 3. The formation of hydroxylated metabolites could successfully be inhibited by co-administration of ketoconazole, a known CYP3A4/5 inhibitor. 4. Besides phase I metabolites, a number of conjugated metabolites were detected using high-resolution mass spectrometry. The most abundant metabolites detected were structurally identified by (1)H NMR as two N-glucosides. NMR analysis strongly suggested that the glycosylation occurred at the two nitrogens (either one in each case) of the imidazole ring. 5. Distribution of midazolam and the glucose conjugates were successfully measured using desorption electrospray mass spectrometry imaging revealing time-dependent changes in distribution over time. 6. In conclusion, it appears that an enzyme with functionality similar to human CYP3A4/5 is present in locusts. However, it appears that conjugation with glucose is the main detoxification pathway of midazolam in locusts.
authors.affiliation: a Department of Pharmacy , and.
authors.forename: Line Rørbæk
authors.initials: LR
authors.lastname: Olsen
authors.affiliation: a Department of Pharmacy , and.
authors.forename: Charlotte
authors.initials: C
authors.lastname: Gabel-Jensen
authors.affiliation: b Department of Drug Design and Pharmacology, Faculty of Health and Medical Sciences , University of Copenhagen , Copenhagen , Denmark , and.
authors.forename: Sileshi Gizachew
authors.initials: SG
authors.lastname: Wubshet
authors.affiliation: b Department of Drug Design and Pharmacology, Faculty of Health and Medical Sciences , University of Copenhagen , Copenhagen , Denmark , and.
authors.forename: Kenneth Thermann
authors.initials: KT
authors.lastname: Kongstad
authors.affiliation: a Department of Pharmacy , and.
authors.forename: Christian
authors.initials: C
authors.lastname: Janfelt
authors.affiliation: c Department of Discovery ADME , H. Lundbeck A/S , Valby , Denmark.
authors.forename: Lassina
authors.initials: L
authors.lastname: Badolo
authors.affiliation: a Department of Pharmacy , and.
authors.forename: Steen Honoré
authors.initials: SH
authors.lastname: Hansen
mesh_terms: D000818:Animals; D002851:Chromatography, High Pressure Liquid; D051544:Cytochrome P-450 CYP3A / Q000378:metabolism*; D065692:Cytochrome P-450 CYP3A Inhibitors / Q000008:administration & dosage; D006031:Glycosylation; D006110:Grasshoppers / Q000378:metabolism*; D019476:Insect Proteins / Q000378:metabolism*; D007654:Ketoconazole / Q000008:administration & dosage; D008279:Magnetic Resonance Imaging; D008297:Male; D008874:Midazolam / Q000378:metabolism*
chemical_list: D065692:Cytochrome P-450 CYP3A Inhibitors; D019476:Insect Proteins; D051544:Cytochrome P-450 CYP3A; D008874:Midazolam; D007654:Ketoconazole
keywords: DESI-MS imaging; S. gregaria; mass spectrometry; metabolite identification; pharmacokinetics