Dietary L-leucine supplementation enhances intestinal development in suckling piglets.

Abstract

L-Leucine is a signaling amino acid in animal metabolism. It is unknown whether supplementing L-leucine to breast-fed neonates may enhance their small-intestinal development. This hypothesis was tested with a piglet model. Seven-day-old sow-reared pigs with an average birth weight of 1.45 kg were assigned randomly to the control or leucine group (n = 30/group). Piglets in the leucine group were orally administrated with 1.4 g L-leucine/kg body weight, whereas piglets in the control group received isonitrogenous L-alanine, twice daily for 14 days. The supplemental L-leucine amounted to 200 % of L-leucine intake from sow's milk by 7-day-old pigs. At the end of the 2-week experiment, tissue samples were collected for determining intestinal morphology, expression of genes for intestinal leucine transporters (real-time RT-PCR and western blot analysis), and plasma metabolites and hormones. L-leucine administration increased (P < 0.05) villus height in the duodenum, an elevated ratio of villus height to crypt depth in the duodenum and ileum, plasma concentrations of leucine, glutamine and asparagine, as well as body-weight gains. mRNA levels for L-leucine transporters (SLC6A14, SLC6A19 and SLC7A9) and the abundance of the ATB(0,+) protein were increased (P < 0.05) but those for SLC7A7 mRNA and the LAT2 protein were decreased (P < 0.05) in the jejunum of leucine-supplemented piglets, compared with the control. Plasma concentrations of ammonia, urea, triglycerides, and growth-related hormones did not differ between the control and leucine groups. Collectively, these results indicate that L-leucine supplementation improves intestinal development and whole-body growth in suckling piglets with a normal birth weight.

• Authors: Yuli Sun, Zhenlong Wu, Wei Li, Chen Zhang, Kaiji Sun, Yun Ji, Bin Wang, Ning Jiao, Beibei He, Weiwei Wang, Zhaolai Dai, Guoyao Wu
• Journal: Amino acids (Amino Acids) Vol. 47 Issue 8 Pg. 1517-25 (Aug 2015) ISSN: 1438-2199 [Electronic] Austria
• PMID: 25940921 (Publication Type: Comparative Study, Journal Article, Research Support, Non-U.S. Gov't, Research Support, U.S. Gov't, Non-P.H.S.)

Chemical References

• Amino Acid Transport Systems
• Amino Acids
• Leucine
• Alanine

Topics

• Alanine (administration & dosage)
• Amino Acid Transport Systems
• Amino Acids (blood)
• Animal Feed
• Animals
• Animals, Suckling
• Dietary Supplements
• Intestine, Small (drug effects, growth & development)
• Leucine (administration & dosage)
• Models, Animal
• Random Allocation
• Sus scrofa
• Weight Gain (drug effects)