The transport of an intact oligopeptide across adult mammalian jejunum.

The passage of an intact nonapeptide across adult rabbit jejunum mounted in an Ussing Chamber is demonstrated with an HPLC system which resolves the renin inhibitor Pro-His-Pro-Phe-His-Leu-Phe-Val-[3H]Phe from all labelled proteolytic cleavage products. Permeability of the peptide (0.016 cm hr-1) is approximately one-seventh that observed for the actively transported 3-0-methyl glucose (0.104 cm hr-1). Flux of the peptide is not changed by the absence of sodium. This study shows that adult mammalian intestine can transport intact oligopeptides and suggests that it will be feasible to develop orally active peptide drugs.