Interrelationships between amino acids absorbed from the isolated pig caecum in situ.

Interrelationships between amino acids absorbed from the isolated pig caecum in situ. Acta Physiol. Pol., 1978, 29 (2): 167--176. Amino acids are absorbed selectively from the caecum of pigs depending on their qualitative and quantitative composition in the intestinal contents. Signigicant interrelationships were found between the absorption of different amino acids. Tyrosine exerted a significant stimulating effect on the absorption of most amino acids absorbed from the caecum, e.g. Asp-NH2, Ser, Thr, Arg, Asp, Glu. An increased absorption of Ser and Thr caused a rise in tyrosine absorption. The absorption of serine and threonine stimulated the absorption of arginine. Serine and threonine competed in the process of absorption, and the activity of serine in this process was much higher, in comparison with that of threonine. Secretion of amino acids back into the intestinal lumen was demonstrated.