Hydrocarbon‐induced changes to metabolic and detoxification enzymes of the Australian crimson‐spotted rainbowfish (Melanotaenia fluviatilis)

Abstract

The toxicity of petroleum hydrocarbons to marine aquatic organisms has been widely investigated; however, the effects on freshwater environments have largely been ignored. Selected biomarkers were measured in a freshwater species, the crimson-spotted rainbowfish (Melanotaenia fluviatilis). Fish were exposed to either a water-accommodated fraction (WAF) of crude oil or a dispersed crude oil water-accommodated fraction (DCWAF) for 3 days and were depurated for 14 days. Generally, biomarkers were altered following the short-term exposures but recovered after 14 days of depuration. Metabolic enzymes measured in gill tissue were citrate synthase and lactate dehydrogenase (LDH). As a result of WAF and DCWAF exposures, citrate synthase and LDH activities increased. Enzyme activities returned to control levels following depuration. Subsequent to the WAF exposure, hepatic ethoxyresorufin-O-deethylase (EROD) activity levels were higher than controls and they returned to control levels during depuration. For the DCWAF exposure, EROD was induced by a TPH (total petroleum hydrocarbons) concentration of 14.5 mg/L; however, after depuration the 14.5 mg/L TPH group had lower EROD activity than did controls. There were no changes in liver- to body-weight ratios or the histopathological organization of gill or liver tissues. As the majority of biomarkers returned to control levels after 14 days of depuration, rainbowfish were able to recover from short-term exposures to crude oil and dispersed crude oil.

Biomarkers involved in energy metabolism and oxidative stress response in the liver ofGoodea gracilisHubbs and Turner, 1939 exposed to the microcystin-producingMicrocystis aeruginosaLB85 strain

“…There are no reports on ADH activity in fish exposed or treated with cyanobacteria or their toxins under environmental or laboratory conditions. Despite the lack of information in this topic, increases in ADH have been related to detoxification of diverse toxic agents, such as PCBs, which are biotransformed by CYP1A1 (Pollino and Holdway, ; Vega‐López et al, ), while CYP2E1 has been shown to be involved in biotransformation of MCs in HepG2 cells (Nong et al, ). In both cases, some of the energy required by these cytochromes (NADH/NAD+) may be provided by the ADH–LDH redox cycle (Vega‐López et al, ).…”

Prooxidant and antioxidant sex-linked response and its relationship to mixed oxidase function enzymes in liver ofAmeca splendens, an endangered goodeid fish exposed to PCBs

“…ADH is able to detoxify the PCB through aerobic metabolism into less harmful forms such as benzoates and 2-hydroxy-penta-2,4-dienolates (Hu¨lsmeyer et al 1998;Vega-Lo´pez, Martı´nez-Tabche, and Galar-Martı´nez 2007). Other mechanisms to offset toxic responses may exist (Fisher et al 2006) as it may be associated with the energy supplies required for the PCB biotransformation (Vijayan et al 2006;Vega-Lo´pez, Martı´nez-Tabche, and Galar-Martı´nez 2007) or for polyaromatic hydrocarbons (Pollino and Holdway 2003). Further studies on the interactions of PCB and ADH are necessary to determine the possible participation of this enzyme in biotransformation of aryl hydrocarbon receptor agonists as seen in the energy supplies for cytoplasmic antioxidant enzymes.…”

Evaluation of chronic toxicity of Kushta Sammulfar (calx of Arsenic trioxide)

“…Petroleum hydrocarbons have been observed to be toxic to aquatic life. Pollino and Holdway 45 observed that a water accommodated fraction of crude oil or dispersed crude oil water accommodated fraction increased the activity of gill citrate synthase at a concentration of 14.5 mg/L. Lipophilic hydrocarbons have been observed to accumulate in the membrane lipid bilayers of microorganisms and interfere with their structural and functional properties.…”