In vitro comparison of hepatic metabolism of 9cis-11 trans and 10trans-12cis isomers of CLA in the rat |
| |
Authors: | Gruffat Dominique De La Torre Anne Chardigny Jean-Michel Durand Denys Loreau Olivier Sébédio Jean-Louis Bauchart Dominique |
| |
Affiliation: | (1) Research Unit on Herbivores, Nutrients and Metabolisms Group, Institut National de la Recherche Agronomique (INRA), 63122 Saint Genès-Champanelle, France;(2) Lipid Nutrition Unit, INRA Dijon, 21065 Dijon, France;(3) Commissariat à l’Energie Atomique (CEA) Saclay, 91191 Gif/Yvette Cedex, France |
| |
Abstract: | Hepatic metabolism of the two main isomers of CLA (9cis-11 trans, 10trans-12cisC18∶2) was compared to that of oleic acid (representative of the main plasma FA) in 16 rats by using the in vitro method of incubated liver slices. Liver tissue samples were incubated at 37°C for 17h under an atmosphere of 95% O2/5%CO2 in a medium supplemented with 0.75 mM of FA mixture (representative of circulating nonesterified FA) and with 55 μM 1-14C]9cis-11 trans C18∶2, 1-14C]10trans-12cis C18∶2, or 1-14C]oleate. The uptake of CLA by hepatocytes was similar for both isomers (9%) and was three times higher (P<0.01) than for oleate (2.6%). The rate of CLA isomer oxidation was two times higher (49 and 40% of incorporated amounts of
9cis-11 trans and 10trans-12 cis, respectively) than that of oleate (P<0.01). Total oxidation of oleate and CLA isomers into 14CO2] was low (2 to 7% of total oxidized FA) compared to the partial oxidation (93 to 98%) leading to the production of 14C] acid-soluble products. CLA isoemrs escaping from catabolism were both highly desaturated (26.7 and 26.8%) into conjugated
18∶3. Oleate and CLA isomers were mainly esterified into neutral lipids (30%). They were slowly secreted as parts of VLDL
particles (<0.4% of FA incorporated into cells), the extent of secretion of oleate and of 10trans-12 cis being 2.2-fold higher than that of 9cis-11 trans (P<0.02). In conclusion, this study clearly showed that both CLA isomers were highly catabolized by hepatocytes, reducing their
availability for peripheral tissues. Moreover, more than 25% of CLA escaping from catabolism was converted into conjugated
18∶3, the biological properties of which remain to be elucidated. |
| |
Keywords: | |
本文献已被 PubMed SpringerLink 等数据库收录! |
|