title: MK-801 is neuroprotective in gerbils when administered during the post-ischaemic period.
abstract: The neuroprotective effects of the non-competitive N-methyl-D-aspartate receptor antagonist (+)-5-methyl-10,11-dihydro-5H-dibenzo[a,d]cyclohepten-5,10-imine maleate (MK-801) have been evaluated in the gerbil hippocampus when the drug was administered i.p. at various times during and after a 5 min period of transient forebrain ischaemia, induced by bilateral common carotid artery occlusion. A single dose of 1, 3 or 10 mg/kg of MK-801 gave significant protection of hippocampal CA1 and CA2 pyramidal neurons when administered during the occlusion and up to 24 h following the period of ischaemia. A dose of 0.3 mg/kg was effective when administered during the occlusion period but gave no protection at 30 min or 2 h post-ischaemia. Experiments in which MK-801 was administered in repeated doses indicated that significant protection was achieved with 1 mg/kg of MK-801 repeated post-ischaemically and with 1 mg/kg MK-801 supplemented with repeated doses of 0.3 mg/kg of MK-801. However 0.3 mg/kg of MK-801 followed by repeated doses of 0.03 mg/kg administered post-ischaemically was not neuroprotective. These results indicate that MK-801 can protect hippocampal neurons from ischaemia-induced neuronal degeneration when it is administered up to 24 h after the insult. These data provide further evidence that therapeutic intervention in the post-ischaemic period can successfully prevent neurodegenerative events, and that the delayed degeneration of hippocampal neurons following an ischaemic insult occurs by an N-methyl-D-aspartate receptor-mediated process.
mesh_terms: D000818:Animals; D003986:Dibenzocycloheptenes / Q000627:therapeutic use*; D016291:Dizocilpine Maleate; D004305:Dose-Response Relationship, Drug; D005260:Female; D005849:Gerbillinae; D006624:Hippocampus / Q000187:drug effects / Q000473:pathology*; D002546:Ischemic Attack, Transient / Q000150:complications / Q000188:drug therapy*; D008297:Male; D009410:Nerve Degeneration / Q000187:drug effects*; D013997:Time Factors
chemical_list: D003986:Dibenzocycloheptenes; D016291:Dizocilpine Maleate