Journal
JOURNAL OF NUTRITION
Volume 140, Issue 5, Pages 893-900Publisher
OXFORD UNIV PRESS
DOI: 10.3945/jn.109.118240
Keywords
-
Categories
Funding
- Research Council of Norway [165203/S40, 172548/S40]
- HelseVest
- University of Bergen (NettMettBAC)
- EC
- University of Salento
- Apulian Region [Cip PS_070, Cip PE_062]
Ask authors/readers for more resources
Atlantic salmon (Salmo salar L.) is one of the most economically important cultured fish and also a key model species in fish nutrition. During digestion, dietary proteins are enzymatically cleaved and a fraction of degradation products in the form of di- and tripeptides translocates from the intestinal lumen into the enterocyte via the Peptide Transporter 1 (PepT1). With this in mind, a full-length cDNA encoding the Atlantic salmon PepT1 (asPepT1) was cloned and functionally characterized. When overexpressed in Xenopus laevis oocytes, asPepT1 operated as a low-affinity/high-capacity transport system, and its maximal transport activity slightly increased as external proton concentration decreased (varying extracellular pH from 6.5 to 8.5). A total of 19 tested di- and tripeptides, some with acknowledged bioactive properties, some containing lysine, which is conditionally growth limiting in fish, were identified as well transported substrates, with affinities ranging between similar to 0.5 and similar to 1.5 mmol/L. Analysis of body tissue distribution showed the highest levels of asPepT1 mRNA in the digestive tract. In particular, asPepT1 mRNA was present in all segments after the stomach, with higher levels in the pyloric caeca and midgut region and lower levels in the hindgut. Depriving salmon of food for 6 d resulted in a similar to 70% reduction of intestinal PepT1 mRNA levels. asPepT1 will allow systematic in vitro analysis of transport of selected di- and tripeptides that may be generated in Atlantic salmon intestine during gastrointestinal transit. Also, asPepT1 will be useful as a marker to estimate protein absorption function along the intestine under various physiological and pathological conditions. J. Nutr. 140: 893-900, 2010.
Authors
I am an author on this paper
Click your name to claim this paper and add it to your profile.
Reviews
Recommended
No Data Available