title: In vivo effects of the soluble fraction of light cycle oil on immune functions in the European sea bass, Dicentrarchus labrax (Linné).
abstract: Hydrocarbons are major contaminants that may affect biota at various trophic levels in estuaries and coastal ecosystems. The effects of accidental pollution by light cycle oil (LCO), a refined product of heavy fuel oil, on bioaccumulation, depuration processes and immune-related parameters in the European sea bass, Dicentrarchus labrax, were investigated in the laboratory after 7 days of exposure and a 2-week recovery period. Exposure of fish to the soluble fraction of LCO (1600ngL(-1)) for 7 days led to the bioaccumulation of some polycyclic aromatic hydrocarbons (PAHs) in muscles: naphthalene, acenaphthene, fluorene, phenanthrene and anthracene. After 7 days of recovery period, half-elimination of naphthalene was reported in fish muscles due to facilitated diffusive loss by the epithelium and a faster elimination rate proven by the presence of a high level of naphthalene biliary metabolites. The other bioaccumulated molecules displayed a slower depuration rate due to their elimination by the formation of hydrophobic metabolites excreted through bile or urine. Three days after the beginning of the recovery period, each contaminated fish showed severe external lesions (tissue necrosis, suppurative exudates, haemorrhagic area). The hypothesis of a possible link with inflammatory phenomenon was supported by (i) an inversion of the leucocyte sub-population percentage, (ii) a significant up-expression in the spleen of the tumour necrosis factor alpha gene, (iii) a significant increase in ACH(50). Moreover, the lack of C3 gene regulation in the spleen suggested a non-renewal of this component. The reduction of phagocytic activity and lysozyme concentration reflected immune suppression. Finally, LCO toxicity in this fish was clearly demonstrated to be related to inflammatory reaction and immune depletion.
authors.affiliation: Anses Laboratoire de Ploufragan-Plouzané, Agence nationale de sécurité sanitaire des aliments, de l'environnement et du travail, Technopôle Brest-Iroise, 29280 Plouzané, France. anne.bado-nilles@ineris.fr
authors.forename: Anne
authors.initials: A
authors.lastname: Bado-Nilles
authors.forename: Claire
authors.initials: C
authors.lastname: Quentel
authors.forename: David
authors.initials: D
authors.lastname: Mazurais
authors.forename: José Luis
authors.initials: JL
authors.lastname: Zambonino-Infante
authors.forename: Michel
authors.initials: M
authors.lastname: Auffret
authors.forename: Hélène
authors.initials: H
authors.lastname: Thomas-Guyon
authors.forename: Stéphane
authors.initials: S
authors.lastname: Le Floch
mesh_terms: D000818:Animals; D001492:Bass / Q000235:genetics / Q000276:immunology* / Q000378:metabolism; D001646:Bile / Q000737:chemistry; D004781:Environmental Exposure / Q000009:adverse effects; D005648:Fuel Oils / Q000633:toxicity*; D005786:Gene Expression Regulation / Q000187:drug effects; D007107:Immune System / Q000187:drug effects*; D007249:Inflammation / Q000139:chemically induced; D007962:Leukocytes / Q000187:drug effects; D009132:Muscles / Q000737:chemistry / Q000187:drug effects; D009281:Naphthalenes / Q000493:pharmacokinetics; D009336:Necrosis / Q000139:chemically induced; D059392:Petroleum Pollution / Q000009:adverse effects; D011084:Polycyclic Aromatic Hydrocarbons / Q000493:pharmacokinetics / Q000633:toxicity; D012623:Seawater / Q000737:chemistry
chemical_list: D005648:Fuel Oils; D009281:Naphthalenes; D011084:Polycyclic Aromatic Hydrocarbons; C031721:naphthalene