title: N-methyl-D-aspartate (NMDA)-mediated muscle relaxant action of memantine in rats.
abstract: The present study examined in vivo whether memantine exerts muscle relaxant activity via an antagonistic action at N-methyl-D-aspartate (NMDA) receptors. Intraperitoneal (i.p.) administration of memantine, 50-100 mumol/kg, reduced the tonic activity in the electromyogram recorded from the gastrocnemius muscle of spastic mutant rats. This effect was prevented by coadministration of NMDA. Memantine, while not affecting monosynaptic Hoffmann (H)-reflexes, depressed polysynaptic flexor reflexes in anaesthetized rats following i.p. (6.25-100 mumol/kg) or intrathecal (i.t., 10-500 nmol) administration. The latter effect was prevented by i.t. coadministration of NMDA, but not of alpha-amino-3-hydroxy-5-methyl-4-isoxazolepropionic acid (AMPA). These observations suggest that NMDA receptors might be involved in the mediation of the muscle relaxant activity of memantine.
authors.affiliation: Department of Neurology, University of Essen, FRG.
authors.forename: M
authors.initials: M
authors.lastname: Schwarz
authors.forename: F
authors.initials: F
authors.lastname: Block
authors.forename: K H
authors.initials: KH
authors.lastname: Sontag
mesh_terms: D000818:Animals; D004576:Electromyography; D005260:Female; D008297:Male; D008559:Memantine / Q000494:pharmacology*; D009126:Muscle Relaxation / Q000187:drug effects*; D009128:Muscle Spasticity / Q000503:physiopathology*; D016202:N-Methylaspartate / Q000494:pharmacology*; D051381:Rats; D011922:Rats, Mutant Strains / Q000502:physiology; D017208:Rats, Wistar / Q000502:physiology; D016194:Receptors, N-Methyl-D-Aspartate / Q000187:drug effects* / Q000502:physiology
chemical_list: D016194:Receptors, N-Methyl-D-Aspartate; D016202:N-Methylaspartate; D008559:Memantine