Use of biomarkers to assess the effects of in vivo exposure to organochloined and organophosphorous pesticides in the mussels of Agadir Bay (South of Morocco)

摘要

The pesticides constitute one of the major pollutants of the environment; their increased use in relation to the development of agriculture is at the origin of a great number of environmental problems, appearing by noxious effects at various levels of the biological organization. These effects can reach the marine and dul?aquicoles watery ecosystems via the phenomena of scrubbing of the grounds and material haulage rich in potentially toxic residues of pesticides. With an aim of in vivo evaluating pollution by the pesticides via the answer of biomarqueurs at two species of mussel of bay of Agadir: Perna perna and Donax trunculus, an experiment of exposure of these last to 500 μg/l of three pesticides to knowing the 2,4-D (organochlorinated), Malathion (organophosphoré) and carbamate were carried out. The follow-up of the answer of the biomarqueurs: acétylcholinestérase (Aitch) biomarquor of neurotoxicity, Catalase (CAT) and Malonedialdhyde (MDA) biomarquor of oxidizing stress and Glutathion S-Transférase (GST) biomarquor of detoxification of hydrocarbons at summer carried out at different duration during 7 days. The results revealed an overall coherent answer of the various biomarkers; this answer occurred in an early way and varies according to the type of the pesticide and the exposure time. Indeed, the Aitch showed a significant inhibition at the two species as of the first six hours (6h) of exposure and continuous until the end of the experiment almost for all the pesticides tested. This answer is explained by the sensitivity of the Aitch to the pesticide especially organophosphorés recognized by their neurotoxic effect appearing by inhibition of the Aitch. The CAT is induced after 12h of exposure beyond this period a rise of the rates of MDA was recorded at the two species, this result probably testifies to a notable induction of lipoperoxydation due to the free radicals generated by the contamination by the pesticides especially the organochlorinated 2,4-D and carbamate. The GST showed a variable answer according to species' and the type of the pesticide, namely an induction by