The liver was chosen for this study, because previous research demonstrated that methyl
Folidols600 (Bayer S.A.) is a commercial OP pesticide, which contains 600 g/L of the active principle methyl parathion. It is widely used in potato and other plantations
in the Southern Brazil (State of Parana´)and it is considered extremely toxic not only for insects but also for terrestrial and aquatic vertebrates