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: Amino acids are potent inhibitors of bile acid uptake by liver plasma membrane vesicles isolated from suckling rats.
    Author: Bucuvalas JC, Goodrich AL, Blitzer BL, Suchy FJ.
    Journal: Pediatr Res; 1985 Dec; 19(12):1298-304. PubMed ID: 4080448.
    Abstract:
    We studied the effects of amino acids which undergo Na+-coupled cotransport on taurocholate uptake by basolateral liver plasma membrane vesicles prepared from 14-day-old rats. At concentrations similar to the total concentration of Na-dependent amino acids measured in portal blood, the Na+-dependent amino acids, L-alanine and L-glutamine, reduced the initial velocity of Na+-dependent taurocholate uptake and impaired uphill transport of the bile acid. In contrast, the Na+-independent amino acid, 2-aminobicyclo(2,2,1)heptane-2-carboxylic acid, did not affect taurocholate uptake. The inhibitory effect of Na+-dependent amino acids on taurocholate uptake was dose dependent. Taurocholate uptake was electroneutral and the inhibition of bile acid uptake by L-glutamine was not affected by the electrical potential. In the absence of a sodium gradient, but with equal intravesicular and extravesicular sodium concentrations, L-glutamine did not inhibit bile acid uptake. With an inwardly directed Na+ gradient, 22Na+ uptake (8 s) was 27% higher in the presence of L-glutamine (5 mM) than without L-glutamine. Kinetic analysis showed that L-glutamine (5 mM) decreased the maximum velocity of Na+-dependent taurocholate uptake to 59% of control (1.62 +/- 0.20 versus 2.73 +/- 0.30 nmol . mg-1 protein . min-1; p less than 0.002), but had no effect on the taurocholate Km (91.7 +/- 26.4 versus 97.1 +/- 25.4 microM). We conclude that physiologic concentrations of Na+-dependent amino acids markedly inhibit taurocholate uptake by membrane vesicles from 14-day rat livers.(ABSTRACT TRUNCATED AT 250 WORDS)
    [Abstract] [Full Text] [Related] [New Search]