par Blachier, François;Darcy-Vrillon, Béatrice;Sener, Abdullah 
;Duée, Pierre Henri;Malaisse, Willy
Référence Biochimica et biophysica acta. Molecular cell research, 1092, 3, page (304-310)
Publication Publié, 1991
;Duée, Pierre Henri;Malaisse, Willy Référence Biochimica et biophysica acta. Molecular cell research, 1092, 3, page (304-310)
Publication Publié, 1991
Article révisé par les pairs
| Résumé : | Rat enterocytes exposed to L-arginine in the absence of any other exogenous substrate were found to actively metabolize this cationic amino acid. L-Arginine was converted to L-citrulline either directly in a NADPH-sensitive manner thought to be coupled with the generation of NO, or indirectly through the sequence of reactions catalyzed by arginase and ornithine transcarbamylase. A large fraction of L-citrulline and L-ornithine generated from exogenous L-arginine was released in the incubation medium. The production of CO2 and (poly)amines from L-arginine occurred at rates 2 and 3 orders of magnitude lower than that characterizing the net uptake of the cationic amino acid, and this despite the fact that enterocytes were equipped to allow the interconversion of L-ornithine and L-glutamate. It is concluded that the oxidative catabolism of L-arginine in eneterocytes is quantitatively negligible relative to its conversion to L-citrulline and L-ornithine. |
