title: Effects of dietary isoleucine on the immune response, antioxidant status and gene expression in the head kidney of juvenile Jian carp (Cyprinus carpio var. Jian).
abstract: This study was conducted to evaluate the effects of dietary isoleucine (Ile) on the immune response, antioxidant status and gene expression in the head kidney of juvenile Jian carp (Cyprinus carpio var. Jian). Six semi-purified isonitrogenous diets (4.2, 7.0, 9.5, 11.9, 13.9 and 16.9 g Ile kg(-1) diet) were fed to Jian carp (6.9 ± 0.03 g) for 60 days. The results showed that Ile supplementation improved the head kidney index, red and white blood cell counts, anti-hydroxyl radical capacity and the activities of superoxide dismutase, catalase, glutathione peroxidase, glutathione reductase and glutathione-S-transferase (P < 0.05), and decreased the malondialdehyde, protein carbonyl and glutathione contents in the head kidney (P < 0.05). After a 60 day feeding trial, an Aeromonas hydrophila challenge study was conducted for 17 days. Differences in survival rate, leucocyte phagocytic activity, serum lysozyme activity, acid phosphatase activity, haemagglutination titre, complement components 3 and 4, immunoglobulin M level and A. hydrophila agglutination antibody titre followed the same trend as that of the head kidney index (P < 0.05). Furthermore, real time polymerase chain reaction revealed that relative mRNA expression of transforming growth factor β2 and target of rapamycin (TOR) in the head kidney significantly increased with increasing Ile levels (P < 0.05). Conversely, the relative mRNA expression of tumour necrosis factor α, interleukin 10 and eIF4E-binding protein (4E-BP) in the head kidney showed a downward trend (P < 0.05). Collectively, this study indicates that dietary Ile improves the fish immune response, regulates the antioxidant status and cytokine, TOR and 4E-BP gene expression in the head kidney.
authors.affiliation: Animal Nutrition Institute, Sichuan Agricultural University, Sichuan, Ya'an 625014, China.
authors.forename: Juan
authors.initials: J
authors.lastname: Zhao
authors.forename: Yang
authors.initials: Y
authors.lastname: Liu
authors.forename: Jun
authors.initials: J
authors.lastname: Jiang
authors.forename: Pei
authors.initials: P
authors.lastname: Wu
authors.forename: Weidan
authors.initials: W
authors.lastname: Jiang
authors.forename: Shuhong
authors.initials: S
authors.lastname: Li
authors.forename: Ling
authors.initials: L
authors.lastname: Tang
authors.forename: Shengyao
authors.initials: S
authors.lastname: Kuang
authors.forename: Lin
authors.initials: L
authors.lastname: Feng
authors.forename: Xiaoqiu
authors.initials: X
authors.lastname: Zhou
mesh_terms: D016980:Aeromonas hydrophila / Q000502:physiology; D000821:Animal Feed / Q000032:analysis; D000818:Animals; D000975:Antioxidants / Q000378:metabolism; D001772:Blood Cell Count / Q000662:veterinary; D002347:Carps / Q000235:genetics* / Q000276:immunology* / Q000378:metabolism; D004032:Diet / Q000662:veterinary; D019587:Dietary Supplements / Q000032:analysis; D004305:Dose-Response Relationship, Drug; D005786:Gene Expression Regulation / Q000187:drug effects*; D060226:Head Kidney / Q000187:drug effects / Q000378:metabolism; D007113:Immunity, Innate / Q000187:drug effects*; D007532:Isoleucine / Q000008:administration & dosage / Q000378:metabolism*; D060888:Real-Time Polymerase Chain Reaction / Q000662:veterinary
chemical_list: D000975:Antioxidants; D007532:Isoleucine
keywords: Antioxidant status; Head kidney; Immune response; Isoleucine; TOR