Metabotropic glutamate receptor 5 antagonist, MPEP, lacks anticonvulsant activity in acute models of epilepsy

Evaluation of the effects of different doses of 2-methyl-6-phenylethynyl-pyridine (MPEP), a selective antagonist of mGluR5, in acute models of epilepsy [pentylenetetrazole (PTZ) and maximal electroconvulsive shock (MES)], dosage relations and also whether if this effect is enhanced by conventional antiepileptic drugs. The anticonvulsant properties of MPEP were examined in mice who received MPEP by intracerebroventricular infusion prior to a subcutaneous injection of pentylenetetrazole and maximal electroshock. Evaluations of convulsive seizures caused by PTZ were performed by the loss of righting reflex while convulsive seizures caused by MES were performed by the occurence of tonic hind limb extension in adult mice. There was no significant difference in both groups (PTZ, MES) when compared with the control group. The present results do not support a significant anticonvulsant potential of MPEP on adult mice as a selective antagonist of mGluR5 in convulsive seizures.