title: [The ratio between the initial stages of assimilation of intact and hydrolyzed dipeptides in rat small intestine].
abstract: Absorption of amino acids and dipeptides in the intestine may be coupled with sodium or proton, respectively. In both cases, when these nutrients are added to the mucosal solution (solution bathing the mucosa) through the epithelial layer should flow additional electric current. which is the most convenient to register by the short-circuit current method (SCC). It was shown that at pH 8.5, we can observe more efficient dipeptide transport (SCC response amplitudes on dipeptides have greater amplitude then SCC responses to equimolar mixture of the corresponding amino acid). In contrast, at pH 5.5 we observe the reverse situation - the SCC responses to mixture of amino acids are more then SCC responses to dipeptides. Increased with pH sodium dependent component of the stimulating effect of easily hydrolysable dipeptides is due to the membrane digestion. Sodium independent effect of dipeptides assimilation decreasing with pH caused by, apparently, functioning of proton-dependent transporter PepT1 for oligopeptides in the apical membrane of enterocytes. We believe that sequential "conditioning" of the stomach contents in the ever-increasing pH while its moving along the gastrointestinal tract (from stomach to colon) enables optimal use of both the mechanism of absorption of oligodipeptides, which is accompanied by a more complete digestion of oligodipeptides.
authors.forename: S T
authors.initials: ST
authors.lastname: Metel'skiĭ
mesh_terms: D000596:Amino Acids / Q000737:chemistry / Q000378:metabolism; D000818:Animals; D004151:Dipeptides / Q000737:chemistry / Q000378:metabolism*; D020895:Enterocytes / Q000378:metabolism* / Q000502:physiology; D006868:Hydrolysis; D007408:Intestinal Absorption / Q000502:physiology*; D007421:Intestine, Small / Q000378:metabolism* / Q000502:physiology; D051381:Rats; D012964:Sodium / Q000378:metabolism
chemical_list: D000596:Amino Acids; D004151:Dipeptides; D012964:Sodium