Nutrient transport in the small intestine: Na+,K +-ATPase expression and activity in the small intestine of the chicken as influenced by dietary sodium

O. Gal-Garber, S. J. Mabjeesh, D. Sklan, Z. Uni*

*Corresponding author for this work

Research output: Contribution to journalArticlepeer-review

66 Scopus citations

Abstract

The Na+-K+-ATPase, localized in the basolateral membrane of enterocytes plays a major role in nutrient transport in the small intestine by transferring K+ ions into- and Na+ out of the cell. Within the enterocyte, homeostasis is maintained by active exclusion of Na from the cell by the Na+, K+-adenosine triphosphatase (ATPase) or sodium pump. Because much of the intestinal nutrient transport is by Na cotransporters, Na+, K+-ATPase may be used to evaluate nutrient uptake. In this study, nutrient transport was evaluated by determining expression and activity of Na+-K+-ATPase in the jejunum of chicks fed diets with different concentrations of Na. Expression of the chicken Na+-K+-ATPase gene was examined following isolation of an 1,140 bp cDNA fragment of the α-subunit using a reverse transcription (RT)-PCR reaction with specific primers. This fragment was sequenced and showed 95 to 98% homology with the mammalian α-subunit of the Na+-K+-ATPase genes. This cDNA fragment was used as a specific probe in Northern blot hybridization for determination of expression in the chicken jejunum. Expression of mRNA of Na+-K+-ATPase was enhanced at low dietary Na but was unchanged at high dietary Na concentrations. In contrast, activity of the enzyme was low with low dietary Na and unchanged at high dietary Na. The Vmax of the Na+-K +-ATPase was unchanged, but affinity was altered by dietary Na concentrations. Thus, determination of expression and activity of intestinal Na+-K+-ATPase allows clearer understanding of changes in intestinal uptake due to dietary Na.

Original languageAmerican English
Pages (from-to)1127-1133
Number of pages7
JournalPoultry Science
Volume82
Issue number7
DOIs
StatePublished - Jul 2003

Keywords

  • Chicken
  • Gene expression
  • Intestine
  • Na-K-ATPase

Fingerprint

Dive into the research topics of 'Nutrient transport in the small intestine: Na+,K +-ATPase expression and activity in the small intestine of the chicken as influenced by dietary sodium'. Together they form a unique fingerprint.

Cite this