title: Daily rhythms in the somatotropic axis of Senegalese sole (Solea senegalensis): The time of day influences the response to GH administration.
abstract: Growth factors in vertebrates display daily rhythms, which, while widely described in mammals, are still poorly understood in teleost fish. Here, we investigated the existence of daily rhythms in the somatotropic axis of the flatfish Solea senegalensis. In a first experiment, daily rhythms of the expression of pituitary adenylate cyclase-activating polypeptide (pacap), growth hormone (gh), insulin-like growth factor 1 (igf1) and its receptor (igf1r) were analyzed under a 12:12 h light:dark cycle. All genes displayed daily rhythms with the acrophases of pacap, gh and igf1 located in the second half of the dark phase (ZT 20:28-0:04 h), whereas the acrophase of igf1r was located around mid-light (ZT 5:33 h). In a second experiment, the influence of the time of day (mid-light, ML, versus mid-darkness, MD) of GH administration on the expression of these factors and on plasma glucose levels was tested. The response observed depended on the time of injection: the strongest effects were observed at MD, when GH administration significantly reduced pituitary gh and enhanced liver igf1 expression. These results provide the first evidence of daily rhythms and differential day/night effects in growth factors in S. senegalensis, suggesting new insights for investigating the physiology of growth and possible applications to improve fish aquaculture.
authors.affiliation: a Department of Physiology, Faculty of Biology, Regional Campus of International Excellence "Campus Mare Nostrum" , University of Murcia , Murcia , Spain.
authors.forename: J F
authors.initials: JF
authors.lastname: López-Olmeda
authors.affiliation: b Department of Biology, Faculty of Marine and Environmental Sciences, Campus de Excelencia Internacional del Mar (CEI-MAR) , University of Cádiz , Cádiz , Spain.
authors.forename: I M
authors.initials: IM
authors.lastname: Pujante
authors.affiliation: a Department of Physiology, Faculty of Biology, Regional Campus of International Excellence "Campus Mare Nostrum" , University of Murcia , Murcia , Spain.|c Department of Animal Science , Federal University of Lavras , Minas Gerais , Brazil.
authors.forename: L S
authors.initials: LS
authors.lastname: Costa
authors.affiliation: d Department of Marine Biology and Aquaculture, Instituto de Ciencias Marinas de Andalucia - CSIC , Cádiz , Spain.
authors.forename: A
authors.initials: A
authors.lastname: Galal-Khallaf
authors.affiliation: b Department of Biology, Faculty of Marine and Environmental Sciences, Campus de Excelencia Internacional del Mar (CEI-MAR) , University of Cádiz , Cádiz , Spain.
authors.forename: J M
authors.initials: JM
authors.lastname: Mancera
authors.affiliation: a Department of Physiology, Faculty of Biology, Regional Campus of International Excellence "Campus Mare Nostrum" , University of Murcia , Murcia , Spain.
authors.forename: F J
authors.initials: FJ
authors.lastname: Sánchez-Vázquez
mesh_terms: D000818:Animals; D001786:Blood Glucose / Q000187:drug effects / Q000378:metabolism; D057906:Circadian Clocks / Q000187:drug effects*; D002940:Circadian Rhythm / Q000187:drug effects*; D029941:Fish Proteins / Q000235:genetics / Q000378:metabolism*; D005412:Flatfishes / Q000235:genetics / Q000378:metabolism*; D013006:Growth Hormone / Q000378:metabolism / Q000494:pharmacology*; D007030:Hypothalamo-Hypophyseal System / Q000187:drug effects* / Q000378:metabolism; D007334:Insulin-Like Growth Factor I / Q000378:metabolism; D008099:Liver / Q000187:drug effects* / Q000378:metabolism; D017440:Photoperiod; D051219:Pituitary Adenylate Cyclase-Activating Polypeptide / Q000378:metabolism; D017526:Receptor, IGF Type 1 / Q000378:metabolism; D013997:Time Factors
chemical_list: D001786:Blood Glucose; D029941:Fish Proteins; D051219:Pituitary Adenylate Cyclase-Activating Polypeptide; D007334:Insulin-Like Growth Factor I; D013006:Growth Hormone; D017526:Receptor, IGF Type 1
keywords: Flatfish; GH chronopharmacology; growth hormone; insulin-like growth factor; pituitary adenylate cyclase-activating polypeptide