Glucuronidation of R- and S-ketoprofen, acetaminophen, and diflunisal by liver microsomes of adjuvant-induced arthritic rats.

Meunier, C J;Verbeeck, Roger-K.
(1999) Drug metabolism and disposition: the biological fate of chemicals — Vol. 27, n° 1, p. 26-31 (1999)

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  • Meunier, C JUCLouvain
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  • Verbeeck, Roger-K.UCLouvain
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Abstract
The effect of adjuvant-induced arthritis on hepatic microsomal glucuronidation was studied in the rat. Arthritis was induced by injection of Mycobacterium butyricum suspended in liquid paraffin. Vmax and the Michaelis-Menten constant values for the in vitro glucuronidation of R- and S-ketoprofen, acetaminophen, and diflunisal by liver microsomes obtained from control and adjuvant-induced arthritic rats were compared. In addition, uridine 5'-diphosphate-glucuronosyltransferase activity toward bilirubin and p-nitrophenol, as well as levels of cytochrome P-450 and beta-glucuronidase were determined in these microsomal preparations. Adjuvant-induced arthritis resulted in a significant reduction in hepatic cytochrome P-450 levels and in p-nitrophenol glucuronidation (5.65 +/- 0.40 versus 2.58 +/- 0.27 micromol.min/mg protein in control and arthritic rats, respectively, mean +/- S.E.M.). Glucuronidation of bilirubin and beta-glucuronidase activities in liver microsomes and in plasma were not affected by adjuvant-induced arthritis. Vmax (nmol/min/mg protein) for the formation of R-ketoprofen glucuronide, S-ketoprofen glucuronide, diflunisal phenolic glucuronide, and diflunisal acyl glucuronide was significantly decreased in arthritic rats (0.68 +/- 0.10, 0.77 +/- 0. 12, 0.044 +/- 0.005, 0.26 +/- 0.03, respectively) compared with control rats (1.45 +/- 0.04, 1.60 +/- 0.04, 0.087 +/- 0.008, 0.46 +/- 0.04, respectively). Glucuronidation of p-nitrophenol, ketoprofen and diflunisal, substrates which seem to be at least partly glucuronidated in the rat by isoenzymes of the UGT2B subfamily, was impaired in adjuvant-induced arthritis. Glucuronidation of bilirubin and acetaminophen, substrates of UGT1- isoenzymes, was not affected by adjuvant-induced arthritis. It seems, therefore, that adjuvant-induced arthritis in the rat leads to impaired glucuronidation of substrates of the UGT2B subfamily.
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Meunier, C. J., & Verbeeck, R.-K. (1999). Glucuronidation of R- and S-ketoprofen, acetaminophen, and diflunisal by liver microsomes of adjuvant-induced arthritic rats. Drug metabolism and disposition: the biological fate of chemicals, 27(1), 26-31. https://hdl.handle.net/2078.5/83379 (Original work published 1999)