Document Detail


Disposition of gemfibrozil and gemfibrozil acyl glucuronide in the rat isolated perfused liver.
MedLine Citation:
PMID:  8886608     Owner:  NLM     Status:  MEDLINE    
Abstract/OtherAbstract:
Acyl glucuronides are reactive electrophilic metabolites and in vivo are readily hydrolyzed, undergo intramolecular rearrangement, and bind covalently to proteins. The isolated perfused liver preparation, using male Sprague-Dawley rats, was used to examine the hepatic disposition of the fibrate hypolipidemic agent gemfibrozil and its acyl glucuronide metabolite, 1-O-gemfibrozil-beta-D-glucuronide. Using a recirculating design, erythrocyte-free perfusion medium containing 1% (w/v) albumin was delivered to the liver via the portal vein at a flow rate of 30 ml/min, and for each experiment was spiked with either gemfibrozil (N = 4) or 1-O-gemfibrozil-beta-D-glucuronide (N = 4) at initial concentrations of 120 microM and 21 microM, respectively. In the gemfibrozil perfusions, the mean (SD) total perfusate clearance, half-life, hepatic extraction ratio of gemfibrozil, and the fraction of eliminated gemfibrozil excreted in bile as the glucuronide conjugate were 2.73 (0.30) ml/min, 76.9 (5.6) min, 0.091 (0.012), and 0.347 (0.154), respectively. In the 1-O-gemfibrozil-beta-D-glucuronide perfusions, the mean (SD) total perfusate clearance, half-life, hepatic extraction ratio, and fraction excreted in bile as the glucuronide conjugate were 19.5 (2.1) ml/min, 8.7 (0.9) min, 0.649 (0.068), and 0.534 (0.077), respectively. The higher hepatic extraction ratio for 1-O-gemfibrozil-beta-D-glucuronide could mostly be attributed to its higher unbound fraction in perfusate (0.182), compared with that of the parent drug (0.004), because the conjugate had a lower intrinsic clearance (305 ml/min) compared with the aglycone (751 ml/min). Control perfusions, conducted in the absence of a liver, showed negligible degradation of 1-O-gemfibrozil-beta-D-glucuronide over 90 min. However, in the presence of a liver, approximately 25% of 1-O-gemfibrozil-beta-D-glucuronide added to perfusate was hydrolyzed to gemfibrozil over 90 min. The study demonstrates the importance of the liver in the formation, uptake, hydrolysis, and excretion of 1-O-gemfibrozil-beta-D-glucuronide.
Authors:
B C Sallustio; B A Fairchild; K Shanahan; A M Evans; R L Nation
Related Documents :
10861968 - Biological disposition of boldine: in vitro and in vivo studies.
723628 - Galactose and glucose metabolism in the isolated perfused suckling and adult rat liver.
3728418 - Fluidity of cadaveric blood after sudden death: part iii. acid-base balance and fibrino...
3816788 - The role of n-glycosylation for the plasma clearance of rat liver secretory glycoproteins.
18446498 - Process optimization, characterization and pharmacokinetic evaluation in rats of ursode...
5040858 - Macromolecular absorption. mechanism of horseradish peroxidase uptake and transport in ...
Publication Detail:
Type:  In Vitro; Journal Article; Research Support, Non-U.S. Gov't    
Journal Detail:
Title:  Drug metabolism and disposition: the biological fate of chemicals     Volume:  24     ISSN:  0090-9556     ISO Abbreviation:  Drug Metab. Dispos.     Publication Date:  1996 Sep 
Date Detail:
Created Date:  1997-02-12     Completed Date:  1997-02-12     Revised Date:  2006-11-15    
Medline Journal Info:
Nlm Unique ID:  9421550     Medline TA:  Drug Metab Dispos     Country:  UNITED STATES    
Other Details:
Languages:  eng     Pagination:  984-9     Citation Subset:  IM    
Affiliation:
Department of Clinical Pharmacology, Queen Elizabeth Hospital, Woodville, South Australia.
Export Citation:
APA/MLA Format     Download EndNote     Download BibTex
MeSH Terms
Descriptor/Qualifier:
Animals
Antilipemic Agents / metabolism*
Bile / metabolism
Gemfibrozil / analogs & derivatives*,  chemistry,  metabolism*,  pharmacokinetics
Glucuronates / chemistry,  metabolism*,  pharmacokinetics
Kinetics
Liver / metabolism*
Male
Perfusion
Rats
Rats, Sprague-Dawley
Chemical
Reg. No./Substance:
0/Antilipemic Agents; 0/Glucuronates; 25812-30-0/Gemfibrozil; 91683-38-4/gemfibrozil 1-O-acylglucuronide

From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine


Previous Document:  Human reductive halothane metabolism in vitro is catalyzed by cytochrome P450 2A6 and 3A4.
Next Document:  Xenobiotic metabolism in rat, dog, and human precision-cut liver slices, freshly isolated hepatocyte...