title: Spleen immune status is affected after acute handling stress but not regulated by cortisol in Eurasian perch, Perca fluviatilis.
abstract: The effects of acute stress on immune status and its regulation by cortisol/corticosteroid receptors have received little attention in percids. To address that question, we investigated the physiological and immune responses of Eurasian perch, Perca fluviatilis to acute stress. We exposed immature perch to an 1-min exondation and measured at 1 h, 6 h, 24 h and 72 h post-stress: (1) stress-related parameters including plasma cortisol and glucose levels, (2) immune parameters in the plasma and in the spleen (complement, respiratory burst and lysozyme activity, total immunoglobulins; gene expression of lysozyme, complement unit 3, apolipoprotein A1 and 14 kDa, hepcidin and chemotaxin) (3) the corticosteroid receptors gene expression in the spleen after having cloned them. In addition, the in vitro effects of cortisol on the spleen immune parameters were also investigated. Plasma cortisol and glucose levels increased markedly 1h post-stress and returned at basal levels after 24 h. P. fluviatilis mineralocorticoid receptor, but not glucocorticoid receptors, was significantly up-regulated both in vivo after the stress and in vitro by cortisol at a physiological concentration (100 ng/ml). The plasma immune parameters were not significantly affected by the stress. In contrast, spleno-somatic index, spleen lysozyme activity, lysozyme and hepcidin gene expression were depleted and total immunoglobulins increased along the whole time-course (1-72 h). But, these immune parameters were not regulated in vitro by cortisol at physiological or supra-physiological doses. Our results indicate that handling stress may affect spleen antibacterial defences without clear effects on circulating immune compounds and that the elevation of plasma cortisol after handling stress may not be related to the regulation of this splenic response.
authors.affiliation: University of Namur, Unit of Research in Organismal Biology, rue de Bruxelles 61, B-5000 Namur, Belgium. sylvain.milla@fundp.ac.be
authors.forename: Sylvain
authors.initials: S
authors.lastname: Milla
authors.forename: Cédric
authors.initials: C
authors.lastname: Mathieu
authors.forename: Neil
authors.initials: N
authors.lastname: Wang
authors.forename: Sophie
authors.initials: S
authors.lastname: Lambert
authors.forename: Stéphanie
authors.initials: S
authors.lastname: Nadzialek
authors.forename: Sophie
authors.initials: S
authors.lastname: Massart
authors.forename: Emilie
authors.initials: E
authors.lastname: Henrotte
authors.forename: Jessica
authors.initials: J
authors.lastname: Douxfils
authors.forename: Charles
authors.initials: C
authors.lastname: Mélard
authors.forename: S N M
authors.initials: SN
authors.lastname: Mandiki
authors.forename: Patrick
authors.initials: P
authors.lastname: Kestemont
mesh_terms: D000818:Animals; D001786:Blood Glucose / Q000032:analysis*; D029941:Fish Proteins / Q000276:immunology; D020869:Gene Expression Profiling; D005786:Gene Expression Regulation / Q000276:immunology*; D006234:Handling, Psychological; D006854:Hydrocortisone / Q000097:blood / Q000276:immunology*; D010471:Perches / Q000276:immunology*; D013154:Spleen / Q000276:immunology*; D013312:Stress, Physiological / Q000276:immunology*; D013997:Time Factors
chemical_list: D001786:Blood Glucose; D029941:Fish Proteins; D006854:Hydrocortisone