title: Seawater and freshwater challenges affect the insulin-like growth factors IGF-I and IGF-II in liver and osmoregulatory organs of the tilapia.
abstract: Contradictory studies suggest IGF-I in fish liver and gills is involved in osmoregulation, but nothing is known about the kidney and intestine's role nor about IGF-II's role in any organ. Tilapia were transferred from freshwater (FW) to seawater (SW) for 1week (wk) and retransferred to FW for another week. At 4h, 1d, 2d, 3d and 1wk after SW-transfer and FW-retransfer IGF-I, IGF-II and growth hormone receptor (GHR1) mRNA were measured by real-time PCR. Hepatic IGF-I, IGF-II and GHR1 mRNA were downregulated in parallel after SW-transfer, recovered and were again downregulated after FW-retransfer. In gills, IGF-I, IGF-II and GHR1 were upregulated synchronously after SW-transfer and, partially also after FW-retransfer. The renal genes were downregulated after SW-transfer and partially upregulated after FW-retransfer. Persisting upregulation in intestinal IGF-I mRNA occurred after FW-retransfer. Thus, endocrine and auto/paracrine IGF-I and IGF-II seem to be involved in fish osmoregulation in an organ-specific manner.
authors.affiliation: Division of Neuroendocrinology, Institute of Anatomy, University of Zürich, Zürich, Switzerland.
authors.forename: Karl
authors.initials: K
authors.lastname: Link
authors.forename: Giorgi
authors.initials: G
authors.lastname: Berishvili
authors.forename: Natallia
authors.initials: N
authors.lastname: Shved
authors.forename: Helena
authors.initials: H
authors.lastname: D'Cotta
authors.forename: Jean-François
authors.initials: JF
authors.lastname: Baroiller
authors.forename: Manfred
authors.initials: M
authors.lastname: Reinecke
authors.forename: Elisabeth
authors.initials: E
authors.lastname: Eppler
mesh_terms: D000818:Animals; D005618:Fresh Water; D005880:Gills / Q000378:metabolism; D007334:Insulin-Like Growth Factor I / Q000235:genetics / Q000378:metabolism*; D007335:Insulin-Like Growth Factor II / Q000235:genetics / Q000378:metabolism*; D007413:Intestinal Mucosa / Q000378:metabolism; D007668:Kidney / Q000378:metabolism; D008099:Liver / Q000378:metabolism*; D009928:Organ Specificity / Q000235:genetics; D011986:Receptors, Somatotropin / Q000235:genetics / Q000378:metabolism; D054712:Salinity; D012623:Seawater; D017210:Tilapia; D014882:Water-Electrolyte Balance / Q000235:genetics
chemical_list: D011986:Receptors, Somatotropin; D007334:Insulin-Like Growth Factor I; D007335:Insulin-Like Growth Factor II