title: Vasotocinergic and isotocinergic systems in the gilthead sea bream (Sparus aurata): an osmoregulatory story.
abstract: To investigate the physiological roles of arginine vasotocin (AVT) and isotocin (IT) in osmoregulatory process in gilthead sea bream (Sparus aurata), a time course study (0, 12h, and 1, 3, 7 and 14 days) has been performed in specimens submitted to hypoosmotic (from 40‰ salinity to 5‰ salinity) or hyperosmotic (from 40‰ salinity to 55‰ salinity) challenges. Plasma and liver osmoregulatory and metabolic parameters, as well as AVT and IT pituitary contents were determined concomitantly with hypothalamic pro-vasotocin (pro-VT) and pro-isotocin (pro-IT) mRNA expression levels. Previously, sequences coding for pro-VT and pro-IT cDNAs were cloned. Two osmoregulatory periods related to plasma osmolality and metabolic parameter variations could be distinguished: i) an adaptative period, from 12h to 3 days after transfer, and ii) a chronic regulatory period, starting at day 3 after transfer. Higher values in hypothalamic pro-VT and pro-IT mRNA expression as well as in pituitary AVT and IT storage levels in both hypo- and/or hyper-osmotic transfers have been distinguished. These increase correlated with changes in plasma cortisol levels, suggesting an interaction between this hormone and pro-VT expression. Furthermore, pro-IT expression enhancement also suggests a role of the isotocinergic system as a modulator in the acute stress response induced by hyper-osmotic challenge in S. aurata.
authors.affiliation: Department of Biology, Faculty of Marine and Environmental Sciences, University of Cádiz, 11510 Puerto Real, Cádiz, Spain; Instituto de Ciencias Marinas de Andalucía (ICMAN), Consejo Superior de Investigaciones Científicas (CSIC), 11510 Puerto Real, Cádiz, Spain. Electronic address: juanantonio.sitcha@uca.es.
authors.forename: J A
authors.initials: JA
authors.lastname: Martos-Sitcha
authors.forename: Y S
authors.initials: YS
authors.lastname: Wunderink
authors.forename: M
authors.initials: M
authors.lastname: Gozdowska
authors.forename: E
authors.initials: E
authors.lastname: Kulczykowska
authors.forename: J M
authors.initials: JM
authors.lastname: Mancera
authors.forename: G
authors.initials: G
authors.lastname: Martínez-Rodríguez
mesh_terms: D000595:Amino Acid Sequence; D000818:Animals; D001483:Base Sequence; D006854:Hydrocortisone / Q000097:blood; D007031:Hypothalamus / Q000378:metabolism; D008297:Male; D008969:Molecular Sequence Data; D009994:Osmolar Concentration; D064587:Osmoregulation / Q000502:physiology*; D010121:Oxytocin / Q000031:analogs & derivatives* / Q000502:physiology; D010902:Pituitary Gland / Q000378:metabolism; D011498:Protein Precursors / Q000737:chemistry / Q000378:metabolism; D054712:Salinity; D021541:Sea Bream / Q000502:physiology*; D016415:Sequence Alignment; D014668:Vasotocin / Q000502:physiology*
chemical_list: D011498:Protein Precursors; D010121:Oxytocin; C008215:isotocin; D014668:Vasotocin; D006854:Hydrocortisone
keywords: Osmoregulation; Pro-isotocin; Pro-vasotocin; Stress; Teleost fish