These tools will no longer be maintained as of December 31, 2024. Archived website can be found here. PubMed4Hh GitHub repository can be found here. Contact NLM Customer Service if you have questions.


Pubmed for Handhelds

PUBMED FOR HANDHELDS

Search MEDLINE/PubMed

  • Title: The influence of luminal pH on transport of neutral and charged dipeptides by rat small intestine, in vitro.
    Author: Lister N, Bailey PD, Collier ID, Boyd CA, Bronk JR.
    Journal: Biochim Biophys Acta; 1997 Mar 13; 1324(2):245-50. PubMed ID: 9092711.
    Abstract:
    Four hydrolysis-resistant dipeptides (D-phenylalanyl-L-alanine, D-phenylalanyl-L-glutamine, D-phenylalanyl-L-glutamate and D-phenylalanyl-L-lysine) were synthesized to investigate the effects of net charge on transmural dipeptide transport by isolated jejunal loops of rat small intestine. At a luminal pH of 7.4 and a concentration of 1 mM the two dipeptides with a net charge of -1 and +1 were transported at substantially slower rates (18 +/- 1.3 and 8.4 +/- 1.3 nmol min(-1)(g dry wt.)(-1), respectively) than neutral D-phenylalanyl-L-alanine and D-phenylalanyl-L-glutamine (87 +/- 0.2 and 197 +/- 14 nmol min(-1)(g dry wt.)(-1), respectively). We investigated the effects of luminal pH on dipeptide transport by varying the NaHCO3 content of Krebs Ringer perfusate equilibrated with 95% 02/5% CO2. The pH changes did not affect water transport, but serosal glucose appearance increased significantly at pH 6.8. Transmural transport of D-phenylalanyl-L-alanine and D-phenylalanyl-L-glutamine at pH 6.8 was stimulated (P < 0.01) by 61% and 49%, respectively, whereas the lower pH increased the rate for negatively charged D-phenylalanyl-L-glutamate by 306% (P < 0.01) and decreased that for positively charged D-phenylalanyl-L-lysine by 46% (P < 0.05). Increasing luminal pH to 8.0 inhibited D-phenylalanyl-L-alanine transport by 60%, whereas D-phenylalanyl-L-lysine transport was 60% faster.
    [Abstract] [Full Text] [Related] [New Search]