The role of nitric oxide (NO) in paraquat (PQ)-induced neurotoxicity is still not fully understood. In this study we used NG-nitro-L-arginine methyl ester (L-NAME), a non-selective nitric oxide synthase (NOS) inhibitor, in order to examine the effects of NO, reactive oxygen species (ROS) generation and lipid peroxidation (LPO) development during PQ-mediated neurotoxicity. Oxidative stress development in the striatum of Wistar rats intrastriatally (i.s.) poisoned with PQ (and in some cases pre-treated with L-NAME) was investigated by measuring superoxide anion (O2 •ˉ), malondialdehyde (MDA) and nitrate (NO3ˉ), 30 min, 24 hours and 7 days after treatment. L-NAME pretreatment provided the possibility to distinguish the role of ROS from reactive nitrogen species (RNS) in oxidative stress development induced by PQ. Our results confi rm the involvement of NO in PQ-mediated neurotoxicity and reduced LPO by L-NAME pretreatment implying that the latter has a protective role.
Influence of iron nutrition in Pb-treated Ailanthus altissima (Mill.) Swingle seedlings was investigated by measurement of photosynthetic efficiency (Fv/Fm), photosynthetic pigment content, and biomass production. The data of Fe-sufficient and Fe-deficient hydroponically grown plants shows that the presence of Fe in growing media in Pb-treated plants increased Fv/Fm compared to Pb-treated plants without Fе. It was also reduced half time, requiring it to reach maximum fluorescence. Chlorophyll as well as carotenoid content did not decrease in Pb-treated A. altissima plants grown with Fe. There was also no significant reduction in root and shoot biomass in all Pb-treated plants when they were constantly supplied with Fe. These results suggest that Fe nutrition increase tolerance to Pb stress in A. altissima plants. This finding could be useful for improving recultivation methods on Pb-polluted sites.