title: L-arginine stimulates CAT-1-mediated arginine uptake and regulation of inducible nitric oxide synthase for the growth of chick intestinal epithelial cells.
abstract: L-arginine (L-Arg) uptake is mediated by members of cationic amino acid transporter (CAT) family and may coincide with the induction of nitric oxide synthases (NOS). The present study was conducted to investigate the extracellular concentrations of L-Arg regulating the CAT-1, CAT-4 and inducible NOS (iNOS) in chick intestinal epithelial cells. The cells were cultured for 4 days in Arg-free Dulbecco's modified Eagle's medium containing 10, 100, 200, 400, or 600 μM L-Arg. Cell viability, nitric oxide (NO) concentrations, uptake and metabolism of L-[3H]-Arg as well as expression of CAT-1, CAT-4, and iNOS were determined. Our results showed that L-Arg enhances cell growth with a maximal response at 10-400 μM. Addition of 100, 200, or 400 μM L-Arg increased the L-[3H]-Arg uptake, which was associated with greater conversion of L-[3H]-citrulline and NO production in comparison with 10 μM L-Arg group. Increasing extracellular concentrations of L-Arg from 10 to 400 μM dose dependently increased the levels of CAT-1 mRNA and protein, while no effect on CAT-4 mRNA abundance was found. Furthermore, supplementation of 100, 200, or 400 μM L-Arg upregulated the expression of iNOS mRNA, and the relative protein levels for iNOS in 200 and 400 μM L-Arg groups were higher than those in 10 and 100 μM L-Arg groups. Collectively, we conclude that the CAT-1 isoform plays a role in L-Arg uptake, and L-Arg-mediated elevation of NO via iNOS promotes the growth of chick intestinal epithelial cells.
authors.affiliation: Key Laboratory for Molecular Animal Nutrition of Ministry of Education, Feed Science Institute, College of Animal Science, Zhejiang University (Zijingang Campus), Hangzhou, 310058, China.
authors.forename: Chao
authors.initials: C
authors.lastname: Yuan
authors.forename: Xiaoyun
authors.initials: X
authors.lastname: Zhang
authors.forename: Qiang
authors.initials: Q
authors.lastname: He
authors.forename: Junming
authors.initials: J
authors.lastname: Li
authors.forename: Jianjun
authors.initials: J
authors.lastname: Lu
authors.forename: Xiaoting
authors.initials: X
authors.lastname: Zou
mesh_terms: D000818:Animals; D001120:Arginine / Q000502:physiology*; D030161:Avian Proteins / Q000378:metabolism*; D001692:Biological Transport; D027201:Cationic Amino Acid Transporter 1 / Q000378:metabolism*; D049109:Cell Proliferation; D002478:Cells, Cultured; D002642:Chick Embryo; D004847:Epithelial Cells / Q000502:physiology*; D015870:Gene Expression; D007413:Intestinal Mucosa / Q000166:cytology; D009569:Nitric Oxide / Q000096:biosynthesis; D052247:Nitric Oxide Synthase Type II / Q000235:genetics / Q000378:metabolism*
chemical_list: D030161:Avian Proteins; D027201:Cationic Amino Acid Transporter 1; D009569:Nitric Oxide; D001120:Arginine; D052247:Nitric Oxide Synthase Type II