title: Growth-promoting effects of sustained swimming in fingerlings of gilthead sea bream (Sparus aurata L.).
abstract: Fish growth is strongly influenced by environmental and nutritional factors and changing culture conditions can help optimize it. The importance of early-life experience on the muscle phenotype later in life is well known. Here, we study the effects of 5 weeks of moderate and sustained swimming activity (5 BL s(-1)) in gilthead sea bream during early development. We analysed growth and body indexes, plasma IGF-I and GH levels, feed conversion, composition [proximate and isotopic ((15)N/(13)C)] and metabolic key enzymes (COX, CS, LDH, HOAD, HK, ALAT, ASAT) of white muscle. Moderate and continuous exercise in fingerlings of gilthead sea bream increased plasma IGF-I, whereas it reduced plasma GH. Under these conditions, growth rate improved without any modification to feed intake through an increase in muscle mass and a reduction in mesenteric fat deposits. There were no changes in the content and turnover of muscle proteins and lipid reserves. Glycogen stores were maintained, but glycogen turnover was higher in white muscle of exercised fish. A lower LDH/CS ratio demonstrated an improvement in the aerobic capacity of white muscle, while a reduction in the COX/CS ratio possibly indicated a functional adaptation of mitochondria to adjust to the tissue-specific energy demand and metabolic fuel availability in exercised fish. We discuss the synergistic effects of dietary nutrients and sustained exercise on the different mitochondrial responses.
authors.affiliation: Departament de Fisiologia i Immunologia, Facultat de Biologia, Universitat de Barcelona, Avinguda Diagonal, 643, 08028, Barcelona, Spain. jblasco@ub.edu.
authors.forename: Josefina
authors.initials: J
authors.lastname: Blasco
authors.affiliation: Departament de Fisiologia i Immunologia, Facultat de Biologia, Universitat de Barcelona, Avinguda Diagonal, 643, 08028, Barcelona, Spain.
authors.forename: A
authors.initials: A
authors.lastname: Moya
authors.affiliation: Departament de Fisiologia i Immunologia, Facultat de Biologia, Universitat de Barcelona, Avinguda Diagonal, 643, 08028, Barcelona, Spain.
authors.forename: A
authors.initials: A
authors.lastname: Millán-Cubillo
authors.affiliation: Departament de Fisiologia i Immunologia, Facultat de Biologia, Universitat de Barcelona, Avinguda Diagonal, 643, 08028, Barcelona, Spain.
authors.forename: E J
authors.initials: EJ
authors.lastname: Vélez
authors.affiliation: Departament de Fisiologia i Immunologia, Facultat de Biologia, Universitat de Barcelona, Avinguda Diagonal, 643, 08028, Barcelona, Spain.
authors.forename: E
authors.initials: E
authors.lastname: Capilla
authors.affiliation: Instituto de Acuicultura Torre de la Sal (IATS-CSIC), Castellón, Spain.
authors.forename: J
authors.initials: J
authors.lastname: Pérez-Sánchez
authors.affiliation: Departament de Fisiologia i Immunologia, Facultat de Biologia, Universitat de Barcelona, Avinguda Diagonal, 643, 08028, Barcelona, Spain.
authors.forename: J
authors.initials: J
authors.lastname: Gutiérrez
authors.affiliation: Departament de Fisiologia i Immunologia, Facultat de Biologia, Universitat de Barcelona, Avinguda Diagonal, 643, 08028, Barcelona, Spain.
authors.forename: J
authors.initials: J
authors.lastname: Fernández-Borrás
mesh_terms: D000367:Age Factors; D000821:Animal Feed; D000818:Animals; D004734:Energy Metabolism; D013006:Growth Hormone / Q000097:blood; D007334:Insulin-Like Growth Factor I / Q000378:metabolism; D008931:Mitochondria, Muscle / Q000378:metabolism; D024510:Muscle Development; D018482:Muscle, Skeletal / Q000254:growth & development* / Q000378:metabolism; D009752:Nutritional Status; D010641:Phenotype; D021541:Sea Bream / Q000097:blood / Q000254:growth & development*; D013550:Swimming
chemical_list: D007334:Insulin-Like Growth Factor I; D013006:Growth Hormone
keywords: COX/CS; Exercise; IGF-I/GH; RNA/DNA; White muscle; δ13C/δ15N