title: Effect of different river flow rates on biomarker responses in common carp (Cyprinus carpio).
abstract: The present study investigated effects of different river flow rates on basal activities of selected biomarkers and the occurrence of oxidative stress in the common carp (Cyprinus carpio). Juvenile carp were exposed to different river flow rates (5-120 cm/s) by caging for 3 weeks. After this period, one half of the fish were sacrificed and used for analysis. The other half received a single intraperitoneal injection of 3-methylcholanthrene (3-MC) and after 6 days were sacrificed and used for analysis. In order to investigate whether the physical activity of carp in the environment will influence the condition status of carp, following biomarkers were measured - activities of glutathione S-transferase (GST), catalase (CAT) and ethoxyresorufin-O-deethylase (EROD) and concentration of protein carbonyls (PC). The results showed that different flow rates significantly influenced biochemical biomarkers. The basal activity of GST did not change significantly after exposure to different river flow rates, whereas the activity of CAT increased with increasing river flow rates. The application of 3-MC caused significant increases in GST and CAT activities, but there were no difference between 3-MC control and 3-MC different flow rates. The occurrence of oxidative stress as a result of exposure to increased physical activity, i.e. increased river flow rates, was confirmed by measurement of PC levels - the level of PC increased with increasing river flow rates. Measurement of EROD basal activity showed that at lower river flow rates the EROD activity increased and at higher river flow rates decreased towards control levels demonstrating a close relationship between oxidative stress, PC levels and EROD activity. Obviously, biomarker responses in carp of different condition status can differ substantially. It can be concluded that flow rate may be an important factor in biomonitoring of rivers using biomarkers and since at different locations river water flow rate can vary significantly, the site selection is extremely important for proper design of river biomonitoring studies involving caging.
authors.affiliation: Department of Biology, Josip Juraj Strossmayer University of Osijek, Cara Hadrijana 8/A, 31000 Osijek, Croatia. Electronic address: hack@biologija.unios.hr.
authors.forename: Branimir K
authors.initials: BK
authors.lastname: Hackenberger
authors.affiliation: Department of Biology, Josip Juraj Strossmayer University of Osijek, Cara Hadrijana 8/A, 31000 Osijek, Croatia. Electronic address: mirna.velki@gmail.com.
authors.forename: Mirna
authors.initials: M
authors.lastname: Velki
authors.affiliation: Department of Biology, Josip Juraj Strossmayer University of Osijek, Cara Hadrijana 8/A, 31000 Osijek, Croatia. Electronic address: zloncaric@biologija.unios.hr.
authors.forename: Zeljka
authors.initials: Z
authors.lastname: Lončarić
authors.affiliation: Department of Biology, Josip Juraj Strossmayer University of Osijek, Cara Hadrijana 8/A, 31000 Osijek, Croatia. Electronic address: davorka@biologija.unios.hr.
authors.forename: Davorka K
authors.initials: DK
authors.lastname: Hackenberger
authors.affiliation: Department of Biology, Josip Juraj Strossmayer University of Osijek, Cara Hadrijana 8/A, 31000 Osijek, Croatia. Electronic address: sandra@biologija.unios.hr.
authors.forename: Sandra
authors.initials: S
authors.lastname: Ečimović
mesh_terms: D000818:Animals; D015415:Biomarkers / Q000378:metabolism; D002347:Carps / Q000378:metabolism*; D002374:Catalase / Q000378:metabolism; D019363:Cytochrome P-450 CYP1A1 / Q000378:metabolism*; D004784:Environmental Monitoring; D005982:Glutathione Transferase / Q000378:metabolism; D008099:Liver / Q000187:drug effects; D008748:Methylcholanthrene / Q000633:toxicity*; D018384:Oxidative Stress / Q000187:drug effects*; D045483:Rivers; D014872:Water Movements
chemical_list: D015415:Biomarkers; D008748:Methylcholanthrene; D002374:Catalase; D019363:Cytochrome P-450 CYP1A1; D005982:Glutathione Transferase
keywords: Biomarkers; Carp; Condition status; Flow rate; Oxidative stress