Biochemical biomarkers in chronically metal-stressed daphnids.
Biochemical biomarkers are a popular measure of toxic effects on organisms due to their assumed fast response, and are usually assessed after acute exposure of the organism to the stressor. However, increasing interest in the use of biochemical biomarkers in environmental pollution monitoring calls for more laboratory long-term studies of contaminants' effects on biochemical endpoints. In this study, four biochemical biomarkers (protein content, activity of cholinesterase (ChE), catalase (CAT) and glutathione S-transferase (GST), were correlated with standardised reproductive and survival endpoints of water fleas (Daphnia magna) after chronic exposure to Cr (VI) and Cd. No effect on the reproduction and survival was noticed up to the highest tested concentration of Cr (VI) (52.5 microg/L), while the protein content, and the ChE and CAT activity decreased, and GST activity increased. Cd affected reproduction of daphnids above 0.656 microg/L, but the protein content and ChE activity were changed at 0.328 microg/L and 0.082 microg/L of Cd, respectively. Biochemical biomarkers in some cases proved to be equally or more sensitive than reproduction and mortality. We recommend more frequent use of a battery of biochemical biomarkers in combination with other higher-level biomarkers also in chronic studies and not only in the acute ones.
Jemec
Anita
A
National Institute of Chemistry, Hajdrihova 19, SI-1000 Ljubljana, Slovenia. anita.jemec@ki.si
Tisler
Tatjana
T
Drobne
Damjana
D
Sepcić
Kristina
K
Jamnik
Polona
P
Ros
Milenko
M
D000818:Animals; D015415:Biomarkers / Q000378:metabolism*; D019256:Cadmium Chloride / Q000633:toxicity*; D002374:Catalase / Q000378:metabolism; D002802:Cholinesterases / Q000378:metabolism; D003621:Daphnia / Q000187:drug effects* / Q000201:enzymology / Q000378:metabolism; D004305:Dose-Response Relationship, Drug; D004784:Environmental Monitoring / Q000379:methods*; D005982:Glutathione Transferase / Q000378:metabolism; D011156:Population Density; D011192:Potassium Dichromate / Q000633:toxicity*; D011506:Proteins / Q000378:metabolism; D015203:Reproducibility of Results; D012098:Reproduction / Q000187:drug effects; D013997:Time Factors; D014874:Water Pollutants, Chemical / Q000633:toxicity*
D015415:Biomarkers; D011506:Proteins; D014874:Water Pollutants, Chemical; D002374:Catalase; D005982:Glutathione Transferase; D002802:Cholinesterases; D019256:Cadmium Chloride; D011192:Potassium Dichromate