Reduction of cerebral infarct size by non-competitive AMPA antagonists in rats subjected to permanent and transient focal ischemia.
Antagonists of 2-amino-3(3-hydroxy-5-methyl-4-isoxazolyl) propionic acid (AMPA) receptors can considerably reduce brain damage after cerebral ischemia, but effectiveness of selective AMPA antagonists has been questioned recently. Therefore, we evaluated the antiischemic efficacy of [+/-]-7-acetyl-5-[4-aminophenyl]-7,8-dihydro-8-cyano-8-methyl-9H-1,3-dioxolo-[4,5-h]-2,3-benzodiazepine (EGIS-8332) and GYKI 53405, two selective, non-competitive AMPA antagonists in two rat models of focal cerebral ischemia. Permanent focal ischemia was produced by electrocoagulation of the middle cerebral artery (MCA). EGIS-8332 and GYKI 53405 were administered 30 min after MCA occlusion at doses of 1, 3 or 10 mg/kg i.p. In transient focal ischemia, MCA was occluded for 1 h and reperfused for 24 h using the intraluminal filament technique and the compounds were given at 3x10 mg/kg i.p. 60, 120 and 180 min following occlusion. In permanent focal ischemia, EGIS-8332 decreased the volume of cerebral infarction both at 10 mg/kg i.p. (36.4%, p<0.01) and at 3 mg/kg i.p. (26.4%, p<0.05) in a dose-dependent manner. GYKI 53405 produced a similar antiischemic effect at 10 mg/kg i.p. (36.4%, p<0.01), but it was ineffective at 3 mg/kg i.p. (6.5%, p=0.57). In transient focal ischemia, EGIS-8332 reduced the volume of necrotic brain tissue (38.7%, p<0.01) and GYKI 53405 was similarly effective (32.6%, p<0.05). Both compounds afforded neuroprotection in the cortical and subcortical regions of the MCA territory. Selective, non-competitive AMPA antagonists administered after the ischemic insult can produce effective neuroprotective action in experimental models of focal cerebral ischemia; therefore, these compounds may be useful as therapeutic agents for the treatment of stroke and neurodegenerative disorders.
Pharmacology Laboratory I, Division of Preclinical Research, EGIS Pharmaceuticals Ltd., 1475 Budapest 10 P.O.B. 100, Budapest, Hungary.
Eva
E
Matucz
Krisztina
K
Móricz
Gábor
G
Gigler
Annamária
A
Simó
József
J
Barkóczy
György
G
Lévay
László G
LG
Hársing
Gábor
G
Szénási
D000818:Animals; D002545:Brain Ischemia / Q000188:drug therapy* / Q000378:metabolism; D002544:Cerebral Infarction / Q000188:drug therapy* / Q000378:metabolism; D018691:Excitatory Amino Acid Antagonists / Q000627:therapeutic use*; D008297:Male; D051381:Rats; D017207:Rats, Sprague-Dawley; D018091:Receptors, AMPA / Q000037:antagonists & inhibitors* / Q000378:metabolism
D018691:Excitatory Amino Acid Antagonists; D018091:Receptors, AMPA