Journal Article

Increases in circulating amino acids with in-feed antibiotics correlated with gene expression of intestinal amino acid transporters in piglets

Zhang, Chuanjian, Yu, Miao, Mu, Chunlong, Zhu, Weiyun, Su, Yong, Huang, Zan, Yang, Yuxiang, Yu, Kaifan

2017

Overview

In-feed antibiotics have been commonly used to promote the growth performance of piglets. The antibiotics can increase protein utilization, but the underlying mechanism is largely unknown. The present study investigated the effects of in-feed antibiotics on intestinal AA transporters and receptors to test the hypothesis that the alteration of circulating AA profiles may be concomitant with the change of intestinal AA transporters and receptors. Sixteen litters of piglets at day 7 started to receive creep feed with (Antibiotic) or without (Control) antibiotic. Piglets were weaned at day 23 after birth, and fed the same diets until day 42. In-feed antibiotics did not affect the BW of 23-day-old ( P  = 0.248), or 42-day-old piglets ( P  = 0.089), but increased the weight gain to feed ratio from day 23 to 42 ( P  = 0.020). At day 42 after birth, antibiotic treatment increased the concentrations of most AAs in serum ( P  < 0.05), and decreased the concentrations of most AAs in jejunal and ileal digesta. Antibiotics upregulated ( P  < 0.05) the mRNA expression levels for jejunal AAs transporters (CAT1, EAAC1, ASCT2, y + LAT1), peptide transporters (PepT1), and Na + –K + –ATPase (ATP1A1), and ileal AA transporters (ASCT2, y + LAT1, b 0,+ AT, and B 0 AT1), and ATP1A1. The antibiotics also upregulated the mRNA expression of jejunal AAs receptors T1R3 and CaSR, and ileal T1R3. Protein expression levels for jejunal AA transporters (EAAC1, b 0,+ AT, and ASCT2) and PepT1 were also upregulated. Correlation analysis revealed that the alterations of AA profiles in serum after the in-feed antibiotics were correlated with the upregulations of mRNA expression levels for key AA transporters and receptors in the small intestine. In conclusion, the in-feed antibiotics increased serum level of most AAs and decreased most AAs in the small intestine. These changes correlated with the upregulations of mRNA expression levels for key AA transporters and receptors in the small intestine. The findings provide further insights into the mechanism of in-feed antibiotics, which may provide new framework for designing alternatives to antibiotics in animal feed in the future.

• Publisher: Springer Vienna,Springer Nature B.V
• Subject: Amino Acid Transport System ASC - agonists / Amino Acid Transport System ASC - genetics / Amino Acid Transport System ASC - metabolism / amino acid transporters / Amino acids / Amino Acids - blood / Analytical Chemistry / Animal feed / Animal Feed - analysis / Animals / Animals, Newborn / Anti-Bacterial Agents - pharmacology / Antibiotics / Biochemical Engineering / Biochemistry / Biological Transport - drug effects / Biomedical and Life Sciences / Birth / blood serum / Body weight gain / Calcium-sensing receptors / correlation / Correlation analysis / Diet / digesta / Excitatory Amino Acid Transporter 3 - agonists / Excitatory Amino Acid Transporter 3 - genetics / Excitatory Amino Acid Transporter 3 - metabolism / feeds / Gene expression / gene expression regulation / Gene Expression Regulation - drug effects / growth performance / Hogs / ileum / jejunum / Kitasamycin - pharmacology / Large Neutral Amino Acid-Transporter 1 - genetics / Large Neutral Amino Acid-Transporter 1 - metabolism / Life Sciences / messenger RNA / Na+/K+-exchanging ATPase / Neurobiology / Original Article / Oxytetracycline - pharmacology / Peptide Transporter 1 - agonists / Peptide Transporter 1 - genetics / Peptide Transporter 1 - metabolism / peptide transporters / piglets / protein synthesis / Proteomics / Quinoxalines - pharmacology / Receptors / Receptors, Calcium-Sensing - agonists / Receptors, Calcium-Sensing - genetics / Receptors, Calcium-Sensing - metabolism / Receptors, G-Protein-Coupled - agonists / Receptors, G-Protein-Coupled - genetics / Receptors, G-Protein-Coupled - metabolism / RNA, Messenger - agonists / RNA, Messenger - genetics / RNA, Messenger - metabolism / Small intestine / Sodium-Potassium-Exchanging ATPase - genetics / Sodium-Potassium-Exchanging ATPase - metabolism / Swine / TRPV Cation Channels - agonists / TRPV Cation Channels - genetics / TRPV Cation Channels - metabolism / Weaning / weight gain / Weight Gain - drug effects