Biochemical endpoints on juvenile Solea senegalensis exposed to estuarine sediments: the effect of contaminant mixtures on metallothionein and CYP1A induction.
Juvenile Solea senegalensis were exposed to fresh sediments from three stations of the Sado estuary (Portugal) in 28-day laboratory assays. Sediments revealed distinct levels of total organic matter, fine fraction, redox potential, trace elements (arsenic, cadmium, chromium, copper, nickel, lead and zinc) and organic contaminants (polycyclic aromatic hydrocarbons, polychlorinated biphenyls and a pesticide: dichloro diphenyl trichloroethane). Organisms were surveyed for contaminant bioaccumulation and induction of two hepatic biochemical biomarkers: metallothionein (MT) and cytochrome P450 (CYP1A), as potential indicators of exposure to metallic and organic contaminants, respectively. Using an integrative approach it was established that, although bioaccumulation is in general accordance with sediment contamination, lethality and biomarker responses are not linearly dependent of the cumulative concentrations of sediment contaminants but rather of their bioavailability and synergistic effects in organisms. It is concluded that metals and organic contaminants modulate both MT and CYP1A induction and it is suggested that reactive oxygen species may be the link between responses and effects of toxicity.
Costa
Pedro M
PM
Instituto do Mar, Departamento de Ciências e Engenharia do Ambiente, Faculdade de Ciências e Tecnologia da Universidade Nova de Lisboa, 2829-516, Caparica, Portugal. pmcosta@fct.unl.pt
Caeiro
Sandra
S
Diniz
Mário S
MS
Lobo
Jorge
J
Martins
Marta
M
Ferreira
Ana M
AM
Caetano
Miguel
M
Vale
Carlos
C
DelValls
T Angel
TA
Costa
Maria H
MH
D000818:Animals; D001189:Aryl Hydrocarbon Hydroxylases / Q000187:drug effects* / Q000378:metabolism; D015415:Biomarkers / Q000378:metabolism; D004790:Enzyme Induction / Q000187:drug effects; D005412:Flatfishes / Q000378:metabolism; D019015:Geologic Sediments / Q000737:chemistry*; D008099:Liver / Q000187:drug effects / Q000378:metabolism; D008668:Metallothionein / Q000187:drug effects* / Q000378:metabolism; D011174:Portugal; D017382:Reactive Oxygen Species / Q000378:metabolism; D014874:Water Pollutants, Chemical / Q000737:chemistry / Q000633:toxicity*
D015415:Biomarkers; D017382:Reactive Oxygen Species; D014874:Water Pollutants, Chemical; D008668:Metallothionein; D001189:Aryl Hydrocarbon Hydroxylases