Formation of three types of glucuronides of 6-hydroxy bile acids by rat liver microsomes.
The glucuronidation of 6-hydroxylated bile acids by rat liver microsomes was studied in vitro; for comparison, several major bile acids lacking a hydroxyl group in position 6 were also investigated. The highest reaction rates were found for lithocholic and deoxycholic acid (10.2 +/- 0.2 and 7.3 +/-...
| Main Authors: | , , , |
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| Format: | Article |
| Language: | English |
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Elsevier
1988-02-01
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| Series: | Journal of Lipid Research |
| Online Access: | http://www.sciencedirect.com/science/article/pii/S0022227520385503 |
| _version_ | 1819293675269652480 |
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| author | P Zimniak A Radominska M Zimniak R Lester |
| author_facet | P Zimniak A Radominska M Zimniak R Lester |
| author_sort | P Zimniak |
| collection | DOAJ |
| description | The glucuronidation of 6-hydroxylated bile acids by rat liver microsomes was studied in vitro; for comparison, several major bile acids lacking a hydroxyl group in position 6 were also investigated. The highest reaction rates were found for lithocholic and deoxycholic acid (10.2 +/- 0.2 and 7.3 +/- 1.4 nmol/mg.min, respectively); our results for these substrates agree well with published values. Glucuronidation rates for the 6 beta-hydroxylated bile acids 3 alpha, 6 beta-dihydroxy-5 beta-cholanoate (murideoxycholate) and 3 alpha, 6 beta, 7 beta-trihydroxy-5 beta-cholanoate (beta-muricholate) were only slightly lower (3.7 +/- 0.3 and 3.6 +/- 0.3 nmol/mg.min). 6 alpha-Hydroxylated bile acids were glucuronidated at rates that were lower than those for their 6 beta-hydroxy counterparts. Rigorous product identification by high-field proton NMR of methyl/acetyl derivatives revealed that while bile acids lacking a 6-hydroxyl group gave rise exclusively to the typical 3-O-glucuronide, the presence of a hydroxyl group in position 6 led to the formation, in ratios depending on the substrate, of three types of conjugate: the 3-O-, the 6-O-, and the carboxyl-linked (acyl-) glucurnide. The latter is the first example of an acyl glucuronide of a bile acid of conventional (C24) size. |
| first_indexed | 2024-12-24T04:14:12Z |
| format | Article |
| id | doaj.art-561c8fbfc8504da293185a940f4ae436 |
| institution | Directory Open Access Journal |
| issn | 0022-2275 |
| language | English |
| last_indexed | 2024-12-24T04:14:12Z |
| publishDate | 1988-02-01 |
| publisher | Elsevier |
| record_format | Article |
| series | Journal of Lipid Research |
| spelling | doaj.art-561c8fbfc8504da293185a940f4ae4362022-12-21T17:15:59ZengElsevierJournal of Lipid Research0022-22751988-02-01292183190Formation of three types of glucuronides of 6-hydroxy bile acids by rat liver microsomes.P Zimniak0A Radominska1M Zimniak2R Lester3Department of Internal Medicine, University of Texas Medical School, Houston 77225.Department of Internal Medicine, University of Texas Medical School, Houston 77225.Department of Internal Medicine, University of Texas Medical School, Houston 77225.Department of Internal Medicine, University of Texas Medical School, Houston 77225.The glucuronidation of 6-hydroxylated bile acids by rat liver microsomes was studied in vitro; for comparison, several major bile acids lacking a hydroxyl group in position 6 were also investigated. The highest reaction rates were found for lithocholic and deoxycholic acid (10.2 +/- 0.2 and 7.3 +/- 1.4 nmol/mg.min, respectively); our results for these substrates agree well with published values. Glucuronidation rates for the 6 beta-hydroxylated bile acids 3 alpha, 6 beta-dihydroxy-5 beta-cholanoate (murideoxycholate) and 3 alpha, 6 beta, 7 beta-trihydroxy-5 beta-cholanoate (beta-muricholate) were only slightly lower (3.7 +/- 0.3 and 3.6 +/- 0.3 nmol/mg.min). 6 alpha-Hydroxylated bile acids were glucuronidated at rates that were lower than those for their 6 beta-hydroxy counterparts. Rigorous product identification by high-field proton NMR of methyl/acetyl derivatives revealed that while bile acids lacking a 6-hydroxyl group gave rise exclusively to the typical 3-O-glucuronide, the presence of a hydroxyl group in position 6 led to the formation, in ratios depending on the substrate, of three types of conjugate: the 3-O-, the 6-O-, and the carboxyl-linked (acyl-) glucurnide. The latter is the first example of an acyl glucuronide of a bile acid of conventional (C24) size.http://www.sciencedirect.com/science/article/pii/S0022227520385503 |
| spellingShingle | P Zimniak A Radominska M Zimniak R Lester Formation of three types of glucuronides of 6-hydroxy bile acids by rat liver microsomes. Journal of Lipid Research |
| title | Formation of three types of glucuronides of 6-hydroxy bile acids by rat liver microsomes. |
| title_full | Formation of three types of glucuronides of 6-hydroxy bile acids by rat liver microsomes. |
| title_fullStr | Formation of three types of glucuronides of 6-hydroxy bile acids by rat liver microsomes. |
| title_full_unstemmed | Formation of three types of glucuronides of 6-hydroxy bile acids by rat liver microsomes. |
| title_short | Formation of three types of glucuronides of 6-hydroxy bile acids by rat liver microsomes. |
| title_sort | formation of three types of glucuronides of 6 hydroxy bile acids by rat liver microsomes |
| url | http://www.sciencedirect.com/science/article/pii/S0022227520385503 |
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