[Peptide transport and peptidase localization in the small intestine of chickens].

The mechanism of peptide transport was studied in vitro in the small intestine of chicks and accumulating preparations of mucosa using glycyl-1-tryptophan. A special criterion was proposed to differentiate the processes of intracellular and membrane hydrolysis of dipeptide basing on the analysis of transport intensity of amino acids released into the serosal solution after hydrolysis of dipeptide. 1-tryptophan released at hydrolysis was transported considerably more slowly than free amino acid. 1-tryptophan from the mixture with glycyne demonstrated the highest transport intensity in serosal solution as well as the highest accumulation in the mucosa cells from all forms of 1-tryptophan. At the same time the peptide form of glycyne was transported with the same intensity as that from the mixture with 1-tryptophan. According to the criterion applied it is supposed that unequal levels of 1-tryptophan and glycyne in the serosal solution prove the membrane hydrolysis of glycyne-1-tryptophan during ist transport in enterocytes.