Estimation of apparent L-amino acid diffusion in porcine jejunal enterocyte brush border membrane

Title:

Estimation of apparent L-amino acid diffusion in porcine jejunal enterocyte brush border membrane

Creator:

Fan, M. Z., Adeola, O., and Asem, E. K.

Identifier:

https://cdk.lib.cas.cz/client/handle/uuid:e20fdd28-f382-4a45-a1f8-3d7ab53461fe
uuid:e20fdd28-f382-4a45-a1f8-3d7ab53461fe
issn:0862-8408

Subject:

Fyziologie člověka a srovnávací fyziologie, aminokyseliny, difuze, prasata, amino acids, diffusion, pigs, enterocyte, brush border membrane vesicles, 14, and 612

Type:

article, články, model:article, and TEXT

Format:

print, bez média, and svazek

Description:

There is an overlap of carrier-mediated L-amino acid transport and apparent simple diffusion when measured in intestinal brush border membrane vesicles. Using L-threonine and L-glutamine as representative amino acids, this study was undertaken to estimate apparent simple diffusion of L-amino acids and to establish the effective dosage of HgCl2 for completely blocking carrier-mediated L-amino acid transport in porcine jejunal enterocyte brush border membrane vesicles. Jejunal mucosa was scraped from three pigs weighing 26 kg. Enterocyte brush border membrane vesicles, with an average enrichment of 24-fold in sucrase specific activity, were prepared by Mg2+-precipitation and differential centrifugation. In vitro uptake was measured by the fast filtration manual procedure. HgCl2 blocked the carrier-mediated initial transport of L-threonine and L-glutamine under Na+-gradient condition in a dose-dependent manner. At the minimal concentration of 0.165 mmol HgCl2 mg-1 protein, carrier-mediated L-threonine and L-glutamine transport was completely inhibited. The apparent L-threonine and L-glutamine diffusion was estimated to be 8.6±0.7 and 12.4±1.0 % of the total uptake at the substrate concentrations of 5 mM (L-threonine) and 50 mM (L-glutamine). Therefore, the treatment of porcine brush border membrane vesicles with a minimum of 0.165 mmol HgCl2 mg-1 protein completely blocks carrier-mediated L-amino acid transport and enables the direct estimation of apparent L-amino acid diffusion in enterocyte brush border membrane vesicles., M. Z. Fan, O. Adeola, E. K. Asem., and Obsahuje bibliografii

Language:

English

Rights:

http://creativecommons.org/licenses/by-nc-sa/4.0/
policy:public

Source:

Physiological research | 2001 Volume:50 | Number:4

Harvested from:

CDK

Metadata only:

false