Inhibitory influence of excitatory amino acid antagonists on penicillin-induced epileptiform bursting in rat hippocampal slices.
The inhibitory influence of excitatory amino acid (E.A.A.) antagonists such as kynurenic acid, 2-amino-5-phosphonopentanoic acid (AP5), cis-2,3-piperidine dicarboxylic acid (cis-2,3 PDA) and (+)-5-methyl-10,11,-dihydro-5H-dibenzo(a,d)cyclo-hepten-5,10-imine maleate (MK 801), has been studied on the epileptiform activity elicited in rat hippocampal slices, bathed in penicillin (1 mM). The rank of the inhibitory potency was: MK 801 greater than kynurenic acid greater than cis 2,3 PDA greater than AP5. Moreover, only MK 801 was able to block the last population spike of the penicillin-induced epileptiform bursting in 100% of the experiments. The data indicate that the antiepileptic activity of E.A.A. antagonists on the penicillin epileptiform bursting in CA1 pyramidal cells is low and limited, indicating that the hippocampal area is not the primary site of the anticonvulsant activity of E.A.A. antagonists.
Laboratorio Farmacologia Istituto Superiore di Sanitá, Roma, Italy.
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Sagratella
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Frank
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de Carolis
D000596:Amino Acids / Q000037:antagonists & inhibitors*; D000818:Animals; D000927:Anticonvulsants / Q000494:pharmacology*; D003986:Dibenzocycloheptenes / Q000494:pharmacology; D016291:Dizocilpine Maleate; D004558:Electric Stimulation; D004594:Electrophysiology; D004827:Epilepsy / Q000139:chemically induced / Q000503:physiopathology*; D006624:Hippocampus / Q000187:drug effects* / Q000502:physiology; D066298:In Vitro Techniques; D007736:Kynurenic Acid / Q000494:pharmacology; D008297:Male; D010406:Penicillins / Q000494:pharmacology*; D051381:Rats; D011919:Rats, Inbred Strains
D000596:Amino Acids; D000927:Anticonvulsants; D003986:Dibenzocycloheptenes; D010406:Penicillins; D016291:Dizocilpine Maleate; D007736:Kynurenic Acid