N-methyl-D-asparate receptor antagonists abolish the maintenance phase of self-sustaining status epilepticus in rat.
We examined the effects of blockers of N-methyl-D-asparate (NMDA) and +/- -alpha-amino-3-hydroxy-5-methylisoxazole-4-propionic acid (AMPA)/kainate receptors on the maintenance of self-sustaining status epilepticus (SSSE) induced in rats by brief intermittent electrical stimulation of the perforant path (PPS). Blocking of NMDA receptor at the PCP site by MK-801 (0.5 mg/kg, i.p.) or ketamine (10 mg/kg, i.p.) as well as at the glycine allosteric site by intrahippocampal 5,7-dichlorokynurenic acid (5,7-DCK, 10 nmol), rapidly and irreversibly aborted both behavioral and electrographic manifestation of SSS. Intrahippocampal injection of the AMPA/kainate receptor blocker 6-cyano7-nitroquinixaline-3-dione (CNQX, 10 nmol) transiently suppressed seizures, which reappeared 4-5 h later. We suggest that the maintenance phase of SSSE depends on activation of NMDA receptors and that NMDA receptor blockers may be a promising class of compounds for the treatment of status epilepticus.
D018750:6-Cyano-7-nitroquinoxaline-2,3-dione / Q000494:pharmacology; D000200:Action Potentials / Q000187:drug effects; D000818:Animals; D000927:Anticonvulsants / Q000494:pharmacology; D004195:Disease Models, Animal; D016291:Dizocilpine Maleate / Q000494:pharmacology; D004558:Electric Stimulation; D018691:Excitatory Amino Acid Antagonists / Q000494:pharmacology; D006624:Hippocampus / Q000737:chemistry* / Q000502:physiology; D007649:Ketamine / Q000494:pharmacology; D007736:Kynurenic Acid / Q000031:analogs & derivatives / Q000494:pharmacology; D008297:Male; D019580:Perforant Pathway / Q000503:physiopathology; D051381:Rats; D017208:Rats, Wistar; D018091:Receptors, AMPA / Q000037:antagonists & inhibitors; D018092:Kainic Acid Receptors / Q000037:antagonists & inhibitors; D016194:Receptors, N-Methyl-D-Aspartate / Q000037:antagonists & inhibitors* / Q000502:physiology*; D013226:Status Epilepticus / Q000188:drug therapy* / Q000503:physiopathology*