title: Neuroendocrine disruption in the shore crab Carcinus maenas: Effects of serotonin and fluoxetine on chh- and mih-gene expression, glycaemia and ecdysteroid levels.
abstract: Serotonin, a highly conserved neurotransmitter, controls many biological functions in vertebrates, but also in invertebrates. Selective serotonin reuptake inhibitors (SSRIs), such as fluoxetine, are commonly used in human medication to ease depression by affecting serotonin levels. Their residues and metabolites can be detected in the aquatic environment and its biota. They may also alter serotonin levels in aquatic invertebrates, thereby perturbing physiological functions. To investigate whether such perturbations can indeed be expected, shore crabs (Carcinus maenas) were injected either with serotonin, fluoxetine or a combination of both. Dose-dependent effects of fluoxetine ranging from 250 to 750nM were investigated. Gene expression of crustacean hyperglycemic hormone (chh) as well as moult inhibiting hormone (mih) was assessed by RT-qPCR at 2h and 12h after injection. Glucose and ecdysteroid levels in the haemolymph were monitored in regular intervals until 12h. Serotonin led to a rapid increase of chh and mih expression. On the contrary, fluoxetine only affected chh and mih expression after several hours, but kept expression levels significantly elevated. Correspondingly, serotonin rapidly increased glycaemia, which returned to normal or below normal levels after 12h. Fluoxetine, however, resulted in a persistent low-level increase of glycaemia, notably during the period when negative feedback regulation reduced glycaemia in the serotonin treated animals. Ecdysteroid levels were significantly decreased by serotonin and fluoxetine, with the latter showing less pronounced and less rapid, but longer lasting effects. Impacts of fluoxetine on glycaemia and ecdysteroids were mostly observed at higher doses (500 and 750nM) and affected principally the response dynamics, but not the amplitude of glycaemia and ecdysteroid-levels. These results suggest that psychoactive drugs are able to disrupt neuroendocrine control in decapod crustaceans, as they interfere with the normal regulation of the serotonergic system.
authors.affiliation: Normandy University, UNIHAVRE, UMR SEBIO, Environmental Stress and Aquatic Biomonitoring, 25 rue Philippe Lebon, F-76063 Le Havre, France.
authors.forename: Alexandrine
authors.initials: A
authors.lastname: Robert
authors.affiliation: Normandy University, UNIHAVRE, UMR SEBIO, Environmental Stress and Aquatic Biomonitoring, 25 rue Philippe Lebon, F-76063 Le Havre, France.
authors.forename: Tiphaine
authors.initials: T
authors.lastname: Monsinjon
authors.affiliation: University of Bordeaux, CNRS UMR 5287, Institut de Neurosciences Cognitives et Intégratives d'Aquitaine (INCIA), Avenue des Facultés, F-33405 Talence Cedex, France.
authors.forename: Jean-Paul
authors.initials: JP
authors.lastname: Delbecque
authors.affiliation: Normandy University, UNIHAVRE, UMR SEBIO, Environmental Stress and Aquatic Biomonitoring, 25 rue Philippe Lebon, F-76063 Le Havre, France.
authors.forename: Stéphanie
authors.initials: S
authors.lastname: Olivier
authors.affiliation: Normandy University, UNIHAVRE, UMR SEBIO, Environmental Stress and Aquatic Biomonitoring, 25 rue Philippe Lebon, F-76063 Le Havre, France.
authors.forename: Agnès
authors.initials: A
authors.lastname: Poret
authors.affiliation: Normandy University, UNIHAVRE, UMR SEBIO, Environmental Stress and Aquatic Biomonitoring, 25 rue Philippe Lebon, F-76063 Le Havre, France.
authors.forename: Frank Le
authors.initials: FL
authors.lastname: Foll
authors.affiliation: Normandy University, UNIHAVRE, Faculty of Science and Technics, 25 rue Philippe Lebon, F-76063 Le Havre, France.
authors.forename: Fabrice
authors.initials: F
authors.lastname: Durand
authors.affiliation: Normandy University, UNIHAVRE, UMR SEBIO, Environmental Stress and Aquatic Biomonitoring, 25 rue Philippe Lebon, F-76063 Le Havre, France. Electronic address: thomas.knigge@univ-lehavre.fr.
authors.forename: Thomas
authors.initials: T
authors.lastname: Knigge
mesh_terms: D000818:Animals; D060829:Arthropod Proteins / Q000235:genetics*; D003386:Brachyura / Q000187:drug effects* / Q000235:genetics / Q000378:metabolism; D026461:Ecdysteroids / Q000235:genetics; D005473:Fluoxetine / Q000633:toxicity*; D005786:Gene Expression Regulation / Q000187:drug effects*; D006458:Hemolymph / Q000737:chemistry; D007447:Invertebrate Hormones / Q000235:genetics; D009419:Nerve Tissue Proteins / Q000235:genetics; D009490:Neurosecretory Systems / Q000187:drug effects; D012701:Serotonin / Q000633:toxicity*; D014874:Water Pollutants, Chemical / Q000633:toxicity
chemical_list: D060829:Arthropod Proteins; D026461:Ecdysteroids; D007447:Invertebrate Hormones; D009419:Nerve Tissue Proteins; D014874:Water Pollutants, Chemical; C015947:hyperglycemic hormone, crustacean; C012445:molt-inhibiting hormone; D005473:Fluoxetine; D012701:Serotonin
keywords: Crustacean hyperglycaemic hormone; Endocrine disruption; Moult inhibiting hormone; Neuropeptides