| Autor: |
Lo, A., Addison, R. S., Hooper, W. D., Dickinson, R. G. |
| Předmět: |
|
| Zdroj: |
Xenobiotica; Jun2001, Vol. 31 Issue 6, p309-319, 11p, 1 Diagram, 1 Chart, 3 Graphs |
| Abstrakt: |
1. An isolated perfused rat liver (IPRL) preparation was used to investigate separately the disposition of the non-steroidal anti-inflammatory drug (NSAID) naproxen (NAP), its reactive acyl glucuronide metabolite (NAG) and a mixture of NAG rearrangement isomers (isoNAG), each at 30µg NAP equivalents ml[sup -1] perfusate (n = 4 each group). 2. Following administration to the IPRL, NAP was eliminated slowly in a log-linear manner with an apparent elimination half-life (t[sub 1/2]) of 13.4 ± 4.4 h. No metabolites were detected in perfusate, while NAG was the only metabolite present in bile in measurable amounts (3.9 ± 0.8% of the dose). Following their administration to the IPRL, both NAG and isoNAG were rapidly hydrolysed (t[sub 1/2] in perfusate = 57 ± 3 and 75 ± 14 min respectively). NAG also rearranged to isoNAG in the perfusate. Both NAG and isoNAG were excreted intact in bile (24.6 and 14.8% of the NAG and isoNAG doses, respectively). 3. Covalent NAP-protein adducts in the liver increased as the dose changed from NAP to NAG to isoNAG (0.20 to 0.34 to 0.48% of the doses, respectively). Similarly, formation of covalent NAP-protein adducts in perfusate were greater in isoNAG-dosed perfusions. The comparative results suggest that isoNAG is a better substrate for adduct formation with liver proteins than NAG. [ABSTRACT FROM AUTHOR] |
| Databáze: |
Complementary Index |
| Externí odkaz: |
|
