Article Text

Download PDFPDF

Chloride dependent amino acid transport in the human small intestine.
  1. L K Munck
  1. Department of Medical Physiology, Panum Institute, Copenhagen, Denmark.


    Carriers of beta amino acids and imino acids in the small intestine of rabbits and guinea pigs are chloride dependent, and a cotransport of chloride, sodium, and 2-methyl-aminoisobutyric acid has been shown. This study examines the chloride dependence of amino acid transport in the human small intestine. The steady state tissue uptake of amino acids, given as the ratio between substrate concentration in intracellular and extracellular water after 35 minutes incubation at 37 degrees C, was determined in mucosal biopsy specimens from the duodenum of patients undergoing diagnostic upper endoscopy and compared using one way analysis of variance. Uptake of leucine and alpha-methyl-D-glucoside in the duodenum and the distal ileum did not differ. The accumulation of all substrates was sodium dependent. In the absence of mucosal chloride the uptake of taurine, glycine, and 2-methyl-aminoisobutyric acid was significantly reduced while that of leucine and alpha-methyl-D-glucoside was unaffected and the reduction of beta alanine uptake not statistically significant. Uptake of 2-methyl-aminoisobutyric acid and proline showed mutual inhibition. Leucine did not reduce uptake of the beta amino acids. In conclusion, chloride dependent transport processes for 2-methyl-amino-isobutyric acid, taurine, and glycine are present in the human small intestine.

    Statistics from

    Request Permissions

    If you wish to reuse any or all of this article please use the link below which will take you to the Copyright Clearance Center’s RightsLink service. You will be able to get a quick price and instant permission to reuse the content in many different ways.