The Role of Energy Metabolism in the Interaction between Amino Acid and Sugar Transport in the Small Intestine

Abstract

Received September 5 , 1972 HIHL-LR, I., and SAWH, P. C. 1973. The role of energy nsetabolism in the interaction between amino acid and sugar transport in the small intestine. Can. J. The interaction between sugar and a~nlno acid transpor-t was studied in everted sacs of rat jejulauln in vitro. The addition of the actively transported nonmetabolized sugars, mgalactose and (1-methyl-uglucoside, to the mucosal medium inhibited the active transport of cycloleucine (1-amino-cyclopentane-I-carboxylic acid). This effect was largely counteracted by the simultaneous presence of D-glucose in the serosal medium or of n-fructose. The results indicate that provision of substrates for energy metabolism relieves the inhibition of transport and supports the hypothesis that the interaction between the intestinal transport of sugar and of amino acid is at least in part due to competition for a limited supply of metabolic energy. BIHLER, I., et SAWH, P. @. 1973. The role of energy metabolism in the interaction between anaino acid and sugar transport in the small intestine. Can. J. Fhysiol. Fharrnacol. 51, 378-382.L'interaction entre le transport des sucres et des acides arnines est etudieein v i~r o dans des sacs renversks de jejunum de rats. Lorsque le D-galactose et I'a-methyl-u-glucoside, sucres transportes activenlent mais non rnetabolises, sont ajoutes du c6tC mucosal, le transport actif de la cyclcucine (acidc 1amino-cyclopentane-1-carboxylique) est inhibe. Cet effet est lnrgement antagonise en la prisence simultanie dai Q-glucose dans le medium sereux, ou du n-fructose. Ces resailtats indiquent qiie I'apport des substrats energetiques soulage I'inhibition du transport et sont a l'appui de l'hypothcse selon laquelle B' interaction ciu transpor-t intestinal des sucres et des acides aminis est due, au moins en partie, a la cornpetition d9utilisation de 1'Cnergie metabolique disponible.Can. J. Physiol. Pharmacol. Downloaded from www.nrcresearchpress.com by San Francisco (UCSF) on 01/02/15For personal use only.