D,L-cis-2,3-pyrrolidine dicarboxylate alters [H-3]-L-glutamate binding and induces convulsions in mice

This study investigated whether D,L-cis-2,3-Pyrrolidine dicarboxylate (D,L-cis-2,3-PDC), a new glutamate analogue, alters glutamate binding to cerebral plasma membranes and whether N-methyl-D-aspartate (NMDA) receptors are involved in the convulsant effect of this compound. D,L-cis-2,3-PDC reduced sodium-independent [H-3]-L-glutamate binding to lysed membrane preparations from adult rat cortex and had no effect on sodium-dependent glutamate binding. Intracerebroventricular administration Of D,L-cis-2,3-PDC (7.5-25 nmol/5 mul) induced generalized tonic-clonic convulsions in mice in a dose-dependent manner. The coadministration of MK-801 (7 nmol/2.5 mul), with D,L-cis-2,3-PDC (16.5 nmol/2.5 mul), fully protected the animals against D,L-cis-2,3-PDC-induced convulsions, while the coadministration of DNQX (10 nmol/2.5 mul) increased the latency to convulsions but did not alter the percentage of animals that had convulsions. These results suggest that D,L-cis-2,3-PDC-induced effects are mediated predominantly by NMDA receptors. (C) 2003 Elsevier Inc. All rights reserved.76229529

The effect of a glyphosate-based herbicide on acetylcholinesterase (AChE) activity, oxidative stress, and antioxidant status in freshwater amphipod: Gammarus pulex (Crustacean)

This study had determined the effect of glyphosate-based herbicide (GBH) on acetylcholinesterase (AChE) enzyme activity, oxidative stress, and antioxidant status in Gammarus pulex. Firstly, the 96-h LC50 value of glyphosate on G. pulex was determined and calculated as 403 μg/L. Subsequently, the organisms were exposed to sub-lethal concentrations (10, 20, and 40 μg/L) of the determined GHB for 24 and 96 h. The samples were taken from control and GBH-treated groups at 24 and 96 h of study and analysed to determine the malondialdehyde (MDA) and reduced glutathione (GSH) levels, the AChE, superoxide dismutase (SOD), catalase (CAT), and glutathione peroxidase (GPx) enzyme activities. In the G. pulex exposed to GBH for 24 and 96 h, the MDA level increased significantly (p < 0.05). The GSH level, the AChE, the CAT, and the GPx activities decreased compared with the control group (p < 0.05). G. pulex exposure to GBH for 24 h showed a temporary reduction in the SOD. GBH exposure led to oxidative stress in the G. pulex as well as affected the cholinergic system of the organism. These results indicated that the parameters measured may be important indicators of herbicide contamination in G. pulex