N-glucuronidation is an important pathway for metabolism and disposition of tertiary amines in humans. This reaction is mainly catalyzed by the enzymes UGT1A4 and UGT2B10. However, the metabolic patterns of UGT1A4- and UGT2B10-mediated N-glucuronidation are not fully clear. In this study, we first optimized in vitro reaction conditions for N-glucuronidation by using specific substrates (i.e., trifluoperazine for UGT1A4, cotinine and amitriptyline for UGT2B10). Furthermore, we found that hepatic N-glucuronidation showed significant species differences. In addition, UGT1A4 and UGT2B10 were primarily responsible for N-glucuronidation of many tertiary amines, including asenapine, loxapine, clozapine, chlorpromazine, dothiepin, doxepin, mirtazapine, mianserin, chlorcyclizine, cyclizine, promethazine, cyclobenzaprine, imatinib, retrorsine, strychnine and brucine. In conclusion, this study provides an in vitro assay system for evaluating N-glucuronidation of amines. Also, UGT1A4- and UGT2B10-mediated N-glucuronidation might play significant roles in metabolism and detoxification of tertiary amines in humans.
Download full-text PDF |
Source |
---|---|
http://dx.doi.org/10.1016/j.jpba.2017.07.037 | DOI Listing |
Clin Transl Sci
December 2024
Division of Clinical Pharmacology, Department of Medicine, Indiana University School of Medicine, Indianapolis, Indiana, USA.
Dexmedetomidine is a centrally acting alpha-2 agonist used for initiation and maintenance of procedural sedation and mechanical ventilation in adult and pediatric settings. It is commonly used in both pediatric and neonatal intensive care units. Dexmedetomidine requires extensive titration, and patients can be over or under-sedated during titration, leading to adverse events such as hypotension and bradycardia, or inadequate sedation, which can result in self-extubation.
View Article and Find Full Text PDFPharmacol Res Perspect
December 2024
Cansearch Research Platform for Pediatric Oncology and Hematology, Faculty of Medicine, Department of Pediatrics, Gynecology and Obstetrics, University of Geneva, Geneva, Switzerland.
UGT2B10 is a phase II drug metabolizing enzyme with limited information on its role in the metabolism of drugs, especially in the pediatric hematopoietic stem cell transplantation setting. Previously, we investigated UGT2B10's role through in silico analyses and prioritized acetaminophen (APAP), lorazepam (LOR), mycophenolic acid (MPA), and voriconazole N-oxide (VCZ N-oxide) for in vitro investigations. In this report, we present in vitro screening of these candidates and of voriconazole (VCZ) to assess their potential to be substrates and/or inhibitors of UGT2B10.
View Article and Find Full Text PDFAAPS J
September 2024
Pharmacokinetics, Dynamics and Metabolism, Pfizer Research and Development, Pfizer Inc., 445 Eastern Point Rd, Groton, CT, 06340, USA.
Lamotrigine is a phenyltriazine anticonvulsant that is primarily metabolized by phase II UDP-glucuronosyltransferases (UGT) to a quaternary N2-glucuronide, which accounts for ~ 90% of the excreted dose in humans. While there is consensus that UGT1A4 plays a predominant role in the formation of the N2-glucuronide, there is compelling evidence in the literature to suggest that the metabolism of lamotrigine is catalyzed by another UGT isoform. However, the exact identity of the UGT isoform that contribute to the formation of this glucuronide remains uncertain.
View Article and Find Full Text PDFDrug Metab Dispos
September 2024
Department of Pharmacokinetics, Dynamics and Metabolism, Pfizer Research and Development, Groton, Connecticut.
UGT2B4 is a highly expressed drug-metabolizing enzyme in the liver contributing to the glucuronidation of several drugs. To enable quantitatively assessing UGT2B4 contribution toward metabolic clearance, a potent and selective UGT2B4 inhibitor that can be used for reaction phenotyping was sought. Initially, a canagliflozin-2'--glucuronyl transferase activity assay was developed in recombinant UGT2B4 and human liver microsomes (HLM) [±2% bovine serum albumin (BSA)].
View Article and Find Full Text PDFPharm Res
August 2024
Department of Pharmaceutical Sciences, Washington State University (WSU), Spokane, WA, 99202, USA.
Purpose: Predicting the quantitative fraction of glucuronidation (f) by individual UDP-glucuronosyltransferase enzymes (UGTs) is challenging due to the lack of selective inhibitors and inconsistent activity of recombinant UGT systems (rUGTs). Our study compares the relative expression versus activity factors (REF versus RAF) to predict f based on rUGT data to human liver and intestinal microsomes (HLM and HIM).
Methods: REF scalars were derived from a previous in-house proteomics study for eleven UGT enzymes (UGT1A1, UGT1A3, UGT1A4, UGT1A6, UGT1A9, UGT1A10, UGT2B4, UGT2B7, UGT2B10, UGT2B15, and UGT2B17), whereas RAF was calculated by measuring activities in rUGTs to microsomes of selective UGT probe substrates.
Enter search terms and have AI summaries delivered each week - change queries or unsubscribe any time!