title: Physiological response of alligator gar juveniles (Atractosteus spatula) exposed to sub-lethal doses of pollutants.
abstract: Alligator gar populations have declined because of overfishing, habitat loss and pollution. Over time, the exposure to different pollutants have affected these fishes as a consequence of their high trophic level, bottom-dwelling habits and long life span. In order to evaluate the physiological effects of pollutants on alligator gar, juveniles (6, 12 and 24 months) were exposed to sub-lethal doses of diazinon, β-naphthoflavone (BNF) and 17 β-estradiol (E2) by intraperitoneal injection. After 2 days of exposure, liver samples were taken to determine the activities of acetylcholinesterase, butyrylcholinesterase and carboxylesterase; alkaline and acid phosphatases (ALP and ACP); ethoxyresorufin o-deethylase (EROD); glutathione s-transferase (GST); superoxide dismutase (SOD), and vitellogenin (VTG) concentration. Two additional bioassays consisting on the exposure of compounds through water or food were performed and after 4 and 28 days, respectively, biomarkers were determined. All esterases were inhibited in organisms exposed to diazinon as well as in 6-months gar exposed to E2 and BNF. In contrast, ALP activity increased in gar exposed to diazinon and E2, while ACP activity did not show any variations. No EROD activity was registered after exposure to the different pollutants, despite being one of the most sensitive and common detoxification biomarkers used for fishes. GST activity reduction was detected when gar were exposed to E2 and BNF, while SOD activity increased after exposure to diazinon and E2. Finally, VTG levels were higher in animals exposed to E2 compared to other treatments. Overall, these results suggest that alligator gar juveniles have a low biotransformation metabolism and show that they are especially sensitive to those pollutants affecting the nervous system.
authors.affiliation: Laboratorio de Ecofisiología, Departamento de Ecología, Facultad de Ciencias Biológicas, Universidad Autónoma de Nuevo León (UANL), Apartado Postal F-96, San Nicolás de los Garza, Nuevo León, C.P. 66450, Mexico.
authors.forename: Carlos Aguilera
authors.initials: CA
authors.lastname: González
authors.forename: Julio
authors.initials: J
authors.lastname: Cruz
authors.forename: Roberto Mendoza
authors.initials: RM
authors.lastname: Alfaro
mesh_terms: D000110:Acetylcholinesterase / Q000378:metabolism; D000135:Acid Phosphatase / Q000378:metabolism; D000469:Alkaline Phosphatase / Q000378:metabolism; D000818:Animals; D002091:Butyrylcholinesterase / Q000378:metabolism; D043182:Carboxylesterase / Q000378:metabolism; D019363:Cytochrome P-450 CYP1A1 / Q000378:metabolism; D003976:Diazinon / Q000633:toxicity*; D004958:Estradiol / Q000633:toxicity*; D005399:Fishes / Q000378:metabolism*; D005982:Glutathione Transferase / Q000378:metabolism; D008099:Liver / Q000187:drug effects / Q000378:metabolism; D013482:Superoxide Dismutase / Q000378:metabolism; D014819:Vitellogenins / Q000378:metabolism; D014874:Water Pollutants, Chemical / Q000633:toxicity*; D019324:beta-Naphthoflavone / Q000633:toxicity*
chemical_list: D014819:Vitellogenins; D014874:Water Pollutants, Chemical; D004958:Estradiol; D019324:beta-Naphthoflavone; D019363:Cytochrome P-450 CYP1A1; D013482:Superoxide Dismutase; D005982:Glutathione Transferase; D043182:Carboxylesterase; D000110:Acetylcholinesterase; D002091:Butyrylcholinesterase; D000469:Alkaline Phosphatase; D000135:Acid Phosphatase; D003976:Diazinon