title: Responses in fish exposed to medetomidine, a new antifouling agent.
abstract: Medetomidine is being introduced as a new antifouling agent. As part of a large risk assessment campaign, we have studied responses to medetomidine in a number of fish species. The studied parameters include respiration, blood parameters, antioxidant enzymes, CYP1A, behaviour, pigmentation, reproduction and growth. The main observations from these studies are: 1. Body paleness was affected at water concentrations in the range of 0.5–50 nM, depending on species.In addition, impaired adaptation to the background colour was shown in fry from turbot and lumpfish. In rainbow trout, desensitization of melanophores (pigment cells) occurred in fish exposed to medetomidine for 21 days, but a prolonged study (54 days exposure time), showed that the melanophores were well functioning and in addition that no apoptosis had occurred. 2. CYP1A activities, measured as EROD activities, were increased at medetomidine water concentrations from 0.5 to 50 nM in rainbow trout, Atlantic salmon, turbot and three-spined stickleback. However, investigations in vitro showed medetomidine to be a potent inhibitor of EROD activity. 3. In lumpfish and turbot fry, a decreased oxygen consumption and respiration rate was observed from 2 nM medetomidine. This effect was reversible to a large extent.
authors.affiliation: Department of Zoology, University of Gothenburg, Sweden. anna.lennguist@zool.gu.se
authors.forename: Anna
authors.initials: A
authors.lastname: Lennquist
authors.forename: Annelie
authors.initials: A
authors.lastname: Hilvarsson
authors.forename: Lars
authors.initials: L
authors.lastname: Förlin
mesh_terms: D000818:Animals; D019363:Cytochrome P-450 CYP1A1 / Q000187:drug effects / Q000378:metabolism; D005399:Fishes / Q000502:physiology*; D020926:Medetomidine / Q000633:toxicity*; D008547:Melanophores / Q000187:drug effects; D010101:Oxygen Consumption / Q000187:drug effects; D018570:Risk Assessment; D014874:Water Pollutants, Chemical / Q000633:toxicity*
chemical_list: D014874:Water Pollutants, Chemical; D019363:Cytochrome P-450 CYP1A1; D020926:Medetomidine