Concentrative amino acid uptake at the serosal side of colon mucosa
Uptake of the nonmetabolizable model amino acid 2-aminoisobutyric acid (=AIB) through the basolateral membrane into epithelial cells was studied in sheep colon stripped of serosa and muscle layers. Only the antiluminal surface of the mucosa was exposed to the incubation medium. Thus AIB entry into epithelial cells could only occur through the basolateral membrane. AIB was taken up by a saturable process against a high concentration gradient. AIB uptake was inhibited by other neutral amino acids but not by sugars. In a low Na+ medium AIB uptake was impaired, indicating that active transport of amino acids through the basolateral membrane of colon epithelial cells is Na+-dependent. In the rat a saturable concentrative uptake of AIB through the basolateral membrane of colon epithelial cells has also been demonstrated.
Concentrative uptake of amino acids through the basolateral membranes is probably important for the supply of colon epithelium with amino acids.
Key wordsColon Amino acid uptake Basolateral membrane Active transport Sheep Rat
Unable to display preview. Download preview PDF.
- 1.Baillien, M., Schoffeniels, E.: Le transport actif d'acides aminés au niveau de l'épithélium intestinal isolé de la tortue grecque. Biochim Biophys. Acta53, 521–536 (1961)Google Scholar
- 2.Batt, E. R., Schachter, D.: Developmental pattern of some intestinal transport mechanisms in newborn rats and mice. Am. J. Physiol.216, 1064–1068 (1969)Google Scholar
- 3.Binder, H. J.: Amino acid absorption from the colon. Biochim. Biophys. Acta219, 503–506 (1970)Google Scholar
- 4.Christensen, H. N., Feldman, B. H., Hastings, A. B.: Concentrative and reversible character of intestinal amino acid transport. Am. J. Physiol.205, 255–260 (1963)Google Scholar
- 5.Cordero, N., Wilson, T. H.: Comparison of transport capacity of small and large intestine. Gastroenterology41, 500–504 (1961)Google Scholar
- 6.Evered, D. H., Nunn, P. B.: Uptake of amino acids by mucosa of rat colon in vitro. Eur. J. Biochem.4, 301–304 (1968)Google Scholar
- 7.James, P. S., Smith, M. W.: Methionine transport by pig colonic mucosa measured during early post-natal development. J. Physiol. (Lond.)262, 151–168 (1976)Google Scholar
- 8.Jarvis, L. G., Morgan, G., Smith, M. W., Wooding, F. B. P.: Cell replacement and changing transport function in the neonatal pig colon. J. Physiol. (Lond.)273, 717–729 (1977)Google Scholar
- 9.Nathans, D., Tapley, D. F., Ross, J. E.: Intestinal transport of amino acids studied in vitro withl-131J]monoiodotyrosine. Biochim. Biophys. Acta41, 271–282 (1960)Google Scholar
- 10.Robinson, J. W. L., Luisier, A. L., Mirkovitch, V.: Transport of amino-acids and sugars by the dog colon mucos. Pflügers Arch.345, 317–326 (1973)Google Scholar
- 11.Scharrer, E., Blatt, J.: In vitro-Untersuchungen zur Aminosäurenaufnahme in die Leber- und Muskelzelle beim Lamm. Zbl. Vet. Med. A23, 121–130 (1976)Google Scholar
- 12.Schultz, S. G., Curran, P. F.: Coupled transport of sodium and organic solutes. Physiol. Rev.50, 637–718 (1970)Google Scholar
- 13.Smith, M. W., James, P. S.: Amino acid transport by the helicoidal colon of the new-born pig. Biochim. Biophys. Acta419, 391–394 (1976)Google Scholar