Intestinal absorption of L-phenylalanine in vitro
- 1 March 1961
- journal article
- research article
- Published by American Physiological Society in American Journal of Physiology-Legacy Content
- Vol. 200 (3), 501-504
- https://doi.org/10.1152/ajplegacy.1961.200.3.501
Abstract
When initially present at the same concentration on both sides, net transport of L-phenylalanine by everted hamster intestinal sacs reached a steady state at 1 hour. The net amount transported, as a function of the final mucosal concentration, was described by a Langmuir adsorption isotherm. An equation was derived showing that the concentration gradient also obeyed such a formulation. Sacs from the midintestine transported more L-phenylalanine than proximal and distal end sacs. Lineweaver-Burk plots of the concentration gradient against final mucosal concentrations showed the process in end sacs to have the same KM (1.8 x 10–3 M) as that in midintestinal sacs; those from midgut, however, had a greater capacity. L-Phenylalanine absorption likely occurs by different amounts of the same mechanism throughout the small intestine. High concentrations of L-phenylalanine resulted in a depression of net transport. The importance of the concentration gradient in revealing the fall in net transport in this and other systems was stressed. l-Phenylalanine transport was also depressed by L-tryptophan and L-methionine.This publication has 4 references indexed in Scilit:
- Accumulation of L-phenylalanine by segments of small intestineAmerican Journal of Physiology-Legacy Content, 1961
- Intestinal transport of l-tryptophan in vitro: inhibition by high concentrationsAmerican Journal of Physiology-Legacy Content, 1960
- Transport of l-tyrosine by the small intestine in vitroAmerican Journal of Physiology-Legacy Content, 1960
- The use of sacs of everted small intestine for the study of the transference of substances from the mucosal to the serosal surfaceThe Journal of Physiology, 1954