title: Cortisol affects metabolic and ionoregulatory responses to a different extent depending on feeding ration in common carp, Cyprinus carpio.
abstract: Interacting effects of feeding and stress on corticoid responses in fish were investigated in common carp fed 3.0% or 0.5% body mass (BM) which received no implant, a sham or a cortisol implant (250 mg/kg BM) throughout a 168 hour post-implant period (168 h-PI). At 12h-PI, cortisol implants elevated plasma cortisol, glucose and lactate. Plasma osmolality and ions remained stable, but cortisol increased gill and kidney Na(+)/K(+) ATPase (NKA) and H(+) ATPase activities. Gill NKA activities were higher at 3%-BM, whereas kidney H(+) ATPase activity was greater at 0.5%-BM. Cortisol induced liver protein mobilization and repartitioned liver and muscle glycogen. At 3%-BM, this did not increase plasma ammonia, reflecting improved excretion efficiency concomitant with upregulation of Rhesus glycoprotein Rhcg-1 in gill. Responses in glucocorticoid receptors (GR1/GR2) and mineralocorticoid receptor (MR) to cortisol elevation were most prominent in kidney with increased expression of all receptors at 24 h-PI at 0.5%-BM, but only GR2 and MR at 0.5%-BM. In the liver, upregulation of all receptors occurred at 24 h-PI at 3%-BM, whilst only GR2 and MR were upregulated at 0.5%-BM. In the gill, there was a limited upregulation: GR2 and MR at 72 h-PI and GR1 at 168 h-PI at 3%-BM but only GR2 at 72 h-PI at 0.5%-BM. Thus cortisol elevation led to similar expression patterns of cortisol receptors in both feeding regimes, while feeding affected the type of receptor that was induced. Induction of corticoid receptors occurred simultaneously with increases in Rhcg-1 mRNA expression (gill) but well after NKA and H(+) ATPase activities increased (gill/kidney).
authors.affiliation: Institute of Tropical Aquaculture, Universiti Malaysia Terengganu, 21030 Kuala Terengganu, Terengganu, Malaysia; School of Fisheries Science and Aquaculture, Universiti Malaysia Terengganu, 20130 Kuala Terengganu, Terengganu, Malaysia; Systemic Physiological and Ecotoxicological Research, Department of Biology, University of Antwerp, Groenenborgerlaan 171, BE-2020 Antwerp, Belgium.
authors.forename: Hon Jung
authors.initials: HJ
authors.lastname: Liew
authors.affiliation: Department of Biological and Environmental Sciences, University of Messina, Viale Ferdinando Stagno d'Alcontres, 31, 98166 S. Agata, Messina, Italy.
authors.forename: Angela
authors.initials: A
authors.lastname: Fazio
authors.affiliation: Department of Biological and Environmental Sciences, University of Messina, Viale Ferdinando Stagno d'Alcontres, 31, 98166 S. Agata, Messina, Italy.
authors.forename: Caterina
authors.initials: C
authors.lastname: Faggio
authors.affiliation: Systemic Physiological and Ecotoxicological Research, Department of Biology, University of Antwerp, Groenenborgerlaan 171, BE-2020 Antwerp, Belgium.
authors.forename: Ronny
authors.initials: R
authors.lastname: Blust
authors.affiliation: Systemic Physiological and Ecotoxicological Research, Department of Biology, University of Antwerp, Groenenborgerlaan 171, BE-2020 Antwerp, Belgium. Electronic address: gudrun.deboeck@uantwerpen.be.
authors.forename: Gudrun
authors.initials: G
authors.lastname: De Boeck
mesh_terms: D000818:Animals; D001786:Blood Glucose / Q000378:metabolism; D002347:Carps / Q000502:physiology*; D027682:Cation Transport Proteins / Q000235:genetics / Q000378:metabolism; D004734:Energy Metabolism / Q000187:drug effects* / Q000502:physiology; D005247:Feeding Behavior / Q000502:physiology*; D029941:Fish Proteins / Q000235:genetics / Q000378:metabolism; D015870:Gene Expression / Q000187:drug effects; D005880:Gills / Q000187:drug effects / Q000378:metabolism; D006003:Glycogen / Q000378:metabolism; D006854:Hydrocortisone / Q000097:blood / Q000494:pharmacology*; D007668:Kidney / Q000187:drug effects / Q000378:metabolism; D007773:Lactates / Q000097:blood; D008099:Liver / Q000187:drug effects / Q000378:metabolism; D009132:Muscles / Q000187:drug effects / Q000378:metabolism; D021381:Protein Transport / Q000187:drug effects; D011965:Receptors, Glucocorticoid / Q000235:genetics / Q000378:metabolism; D018161:Receptors, Mineralocorticoid / Q000235:genetics / Q000378:metabolism; D020133:Reverse Transcriptase Polymerase Chain Reaction; D000254:Sodium-Potassium-Exchanging ATPase / Q000235:genetics / Q000378:metabolism; D014882:Water-Electrolyte Balance / Q000187:drug effects* / Q000502:physiology
chemical_list: D001786:Blood Glucose; D027682:Cation Transport Proteins; D029941:Fish Proteins; D007773:Lactates; D011965:Receptors, Glucocorticoid; D018161:Receptors, Mineralocorticoid; D006003:Glycogen; D000254:Sodium-Potassium-Exchanging ATPase; D006854:Hydrocortisone
keywords: Corticoid receptors; Cyprinid; Energy metabolism; Hydromineral balance; Rhesus glycoprotein; Stress