Neuroprotective effect caused by MPEP, an antagonist of metabotropic glutamate receptor mGluR5, on seizures induced by pilocarpine in 21-day-old rats.
This study was designed to verify the influence of MPEP (2-methyl-6-phenylethynyl pyridine hydrochloride), an antagonist of metabotropic glutamate receptor subtype 5 (mGluR5), in seizures and status epilepticus (SE) induced by pilocarpine in young rats. In order to investigate the protective effect of MPEP on pilocarpine-induced seizures, young male rats (21-day-old) were pretreated by intraperitoneal route (i.p.) with MPEP (1, 5 and 15 mg/kg) before of pilocarpine administration (400 mg/kg, i.p.). The animals were observed for 1 h after injection of pilocarpine (except pilocarpine group) to determine: number of peripheral cholinergic signs, tremors, stereotyped movements, seizures, SE, latency to the first seizure and number of deaths. Pretreatment with MPEP, at all doses, delayed the onset for the first seizure episode induced by pilocarpine in rats. MPEP abolished the mortality rate caused by administration of pilocarpine in rats. Pretreatment with MPEP (5 and 15 mg/kg) protected against the levels of RS (reactive species), CAT (catalase) and glutathione S-transferase (GST) activities in brain of rats altered by pilocarpine administration. MPEP, at all doses, protected acetylcholinsterase (AChE) activity inhibited by pilocarpine administration in rats. The results suggest that anticonvulsant action of MPEP can be attributed to its mGlu5 receptor antagonism. Therefore, blockade of mGlu5 receptors might represent a novel target for the treatment of seizures in young rats.
Jesse
Cristiano R
CR
Laboratório de Síntese, Reatividade e Avaliação Farmacológica e Toxicológica de Organocalcogênios, Centro de Ciências Naturais e Exatas, Universidade Federal de Santa Maria, Santa Maria, CEP 97105-900, RS, Brazil.
Savegnago
Lucielli
L
Rocha
Joao B T
JB
Nogueira
Cristina W
CW
D000110:Acetylcholinesterase / Q000187:drug effects / Q000378:metabolism; D000818:Animals; D001921:Brain / Q000187:drug effects* / Q000378:metabolism / Q000503:physiopathology; D003292:Convulsants; D019610:Cytoprotection / Q000187:drug effects / Q000502:physiology; D004195:Disease Models, Animal; D004305:Dose-Response Relationship, Drug; D004827:Epilepsy / Q000139:chemically induced / Q000378:metabolism / Q000503:physiopathology*; D018691:Excitatory Amino Acid Antagonists / Q000494:pharmacology; D018698:Glutamic Acid / Q000378:metabolism; D008297:Male; D018721:Muscarinic Agonists; D009410:Nerve Degeneration / Q000188:drug therapy* / Q000378:metabolism / Q000503:physiopathology*; D018696:Neuroprotective Agents / Q000494:pharmacology; D018384:Oxidative Stress / Q000187:drug effects / Q000502:physiology; D010862:Pilocarpine; D011725:Pyridines / Q000494:pharmacology*; D051381:Rats; D017208:Rats, Wistar; D064529:Receptor, Metabotropic Glutamate 5; D018094:Receptors, Metabotropic Glutamate / Q000037:antagonists & inhibitors* / Q000378:metabolism; D009435:Synaptic Transmission / Q000187:drug effects / Q000502:physiology; D016896:Treatment Outcome
D003292:Convulsants; D018691:Excitatory Amino Acid Antagonists; C578937:Grm5 protein, rat; D018721:Muscarinic Agonists; D018696:Neuroprotective Agents; D011725:Pyridines; D064529:Receptor, Metabotropic Glutamate 5; D018094:Receptors, Metabotropic Glutamate; D010862:Pilocarpine; D018698:Glutamic Acid; C121465:6-methyl-2-(phenylethynyl)pyridine; D000110:Acetylcholinesterase