title: Regulation of lipid metabolism and peroxisome proliferator-activated receptors in rainbow trout adipose tissue by lipolytic and antilipolytic endocrine factors.
abstract: The aim of this study was to determine the effects of growth hormone (GH) and insulin-like growth factor (IGF)-I on glycerol release and the regulation of IGF-I and IGF-II expression by GH in isolated rainbow trout adipocytes. Cells were also incubated with GH, tumor necrosis factor α (TNFα), or insulin to analyze the gene expression of peroxisome proliferator-activated receptors (PPARs) and lipid metabolism markers: hormone sensitive lipase, fatty acid synthase (FAS), and lipoprotein lipase. Complimentary in vivo experiments were performed by intraperitoneally administering insulin, TNFα, or lipopolysaccharide and subjecting the animals to fasting and refeeding periods. The results showed that IGF-I had an antilipolytic effect and GH had a lipolytic effect; the latter occurred independently of IGF modulation and in conjunction with a reduction in PPARα expression in adipocytes. The anabolic action of insulin was demonstrated through its upregulation of lipogenic genes such as lipoprotein lipase, FAS, and PPARγ, whereas GH, by contrast, inhibited FAS expression in adipose tissue. The gene transcription levels of PPARs changed differentially during fasting and refeeding, and the TNFα and/or lipopolysaccharide administration suggested that the regulation of PPARs helps maintain metabolic adipose tissue homeostasis in rainbow trout.
authors.affiliation: Department of Physiology and Immunology, Faculty of Biology, University of Barcelona, Barcelona 08028, Spain.
authors.forename: L
authors.initials: L
authors.lastname: Cruz-Garcia
authors.affiliation: Department of Physiology and Immunology, Faculty of Biology, University of Barcelona, Barcelona 08028, Spain.
authors.forename: J
authors.initials: J
authors.lastname: Sánchez-Gurmaches
authors.affiliation: Department of Physiology and Immunology, Faculty of Biology, University of Barcelona, Barcelona 08028, Spain.
authors.forename: M
authors.initials: M
authors.lastname: Monroy
authors.affiliation: Department of Physiology and Immunology, Faculty of Biology, University of Barcelona, Barcelona 08028, Spain.
authors.forename: J
authors.initials: J
authors.lastname: Gutiérrez
authors.affiliation: Department of Physiology and Immunology, Faculty of Biology, University of Barcelona, Barcelona 08028, Spain. Electronic address: mnavarro@ub.edu.
authors.forename: I
authors.initials: I
authors.lastname: Navarro
mesh_terms: D017667:Adipocytes / Q000187:drug effects / Q000378:metabolism; D000273:Adipose Tissue / Q000378:metabolism*; D000818:Animals; D005215:Fasting / Q000502:physiology; D064429:Fatty Acid Synthases / Q000235:genetics; D005502:Food; D005786:Gene Expression Regulation / Q000187:drug effects*; D005990:Glycerol / Q000378:metabolism; D013006:Growth Hormone / Q000494:pharmacology; D007328:Insulin / Q000494:pharmacology; D007334:Insulin-Like Growth Factor I / Q000235:genetics / Q000494:pharmacology; D007335:Insulin-Like Growth Factor II / Q000235:genetics; D050356:Lipid Metabolism / Q000235:genetics* / Q000502:physiology; D008066:Lipolysis / Q000187:drug effects*; D008071:Lipoprotein Lipase / Q000235:genetics; D017686:Oncorhynchus mykiss / Q000378:metabolism*; D047492:Peroxisome Proliferator-Activated Receptors / Q000235:genetics* / Q000502:physiology; D002787:Sterol Esterase / Q000235:genetics; D014409:Tumor Necrosis Factor-alpha / Q000494:pharmacology
chemical_list: D007328:Insulin; D047492:Peroxisome Proliferator-Activated Receptors; D014409:Tumor Necrosis Factor-alpha; D007334:Insulin-Like Growth Factor I; D007335:Insulin-Like Growth Factor II; D013006:Growth Hormone; D064429:Fatty Acid Synthases; D002787:Sterol Esterase; D008071:Lipoprotein Lipase; D005990:Glycerol
keywords: Adipose tissue; GH; IGF; Insulin; PPARs; Trout