In vitro and in vivo studies of potential biomarkers of lead and uranium contamination: Lipid peroxidation, acetylcholinesterase, catalase and glutathione peroxidase activities in three non-mammalian species

The aim of this work was to assess the relationships between lead (Pb) and uranium (U) exposure, lipid peroxidation and some enzyme activities in a mollusc (Corbicula sp.), an earthworm (Eisenia fetida) and a fish (Brachydanio rerio). A comparative study was performed both in vitro and in vivo on whole organism postmitochondrial fractions and four potential biomarkers were analysed: a marker of neurotoxicity (acetylcholinesterase activity, AChE, EC 3.1.1.7), a marker of oxidative stress (malondialdehyde (MDA) level), and two markers of hydroperoxide detoxication: catalase (EC 1.11.1.6) and glutathione peroxidase (GPx, EC 1.11.1.9) activities, Our results have shown that the MDA contents were not significantly changed by exposures to lead either in vitro or in vivo. During uranium exposure, the MDA content was increased in vitro (particularly in fish samples) whereas this metal failed to stimulate lipid peroxidation in vivo. With some exceptions, in vitro and in vivo exposures to lead and uranium showed that the AChE, catalase and GPx activities were decreased in the three species. These exceptions indicated that different mechanisms occurred in the different species. In conclusion, it was shown that S9 fractions of whole organisms could be useful for environmental contamination biomonitoring. Moreover, it was shown that AChE activities were modulated by metals in vivo and cannot be considered as specific biomarkers of organophosphorus or carbamate pesticide exposure. Acetylcholinesterase and catalase activities could be used to survey lead and uranium contamination.