title: Trans-mucosal passage of intact peptides in the guinea-pig small intestine in vivo: a re-appraisal.
abstract: 1. Re-examination of data for the chemical analysis of peptide-bound amino acids in the mesenteric venous blood of anaesthetized guinea-pigs suggests that there are small, but significant, amounts of small peptides in the blood of fasted animals. 2. Furthermore, there is a significant increase in the peptide content of the mesenteric venous blood during intraduodenal infusion of a partial digest of casein. 3. The data are consistent with the view that some 10% of the amino nitrogen entering the mesenteric blood during absorption of a casein digest in vivo may be in the form of small peptides, although it is not possible to define confidence limits for this estimate.
mesh_terms: D000596:Amino Acids / Q000097:blood; D000818:Animals; D001692:Biological Transport; D002364:Caseins / Q000378:metabolism; D004386:Duodenum / Q000378:metabolism*; D006168:Guinea Pigs; D007408:Intestinal Absorption; D007413:Intestinal Mucosa / Q000378:metabolism*; D008642:Mesenteric Veins; D010455:Peptides / Q000378:metabolism*; D011485:Protein Binding
chemical_list: D000596:Amino Acids; D002364:Caseins; D010455:Peptides