Effects of the epileptogenic agent strychnine on membrane currents elicited by agonists of the NMDA and non-NMDA receptors in Xenopus oocytes.
The effects of strychnine (STRY) on ion channels activated by N-methyl-D-aspartate (NMDA), kainate (KA), alpha-amino-3-hydroxy-5-methyl-4-isoxazolpropionate (AMPA) and quisqualate (QUIS) were studied using Xenopus oocytes, microinjected with mRNA from rats' brains. STRY reduced NMDA-, KA- and AMPA-induced membrane currents in a dose-dependent manner. The effect was more pronounced with NMDA than with KA and AMPA. QUIS-induced membrane currents were not affected by STRY. The depressive effect of STRY on NMDA responses was voltage dependent. The effect of STRY on the NMDA-induced membrane currents remains unchanged when the concentration of NMDA or glycine was increased. Intracellular injection of STRY did not alter the NMDA response.
Musshoff
U
U
Institut für Physiologie, Münster, Germany.
Madeja
M
M
Bloms-Funke
P
P
Speckmann
E J
EJ
D000818:Animals; D004594:Electrophysiology; D005998:Glycine / Q000494:pharmacology; D007473:Ion Channels / Q000187:drug effects*; D007608:Kainic Acid / Q000494:pharmacology; D016202:N-Methylaspartate / Q000494:pharmacology; D009865:Oocytes / Q000737:chemistry* / Q000648:ultrastructure*; D016318:Quisqualic Acid / Q000494:pharmacology; D012333:RNA, Messenger / Q000008:administration & dosage; D051381:Rats; D018091:Receptors, AMPA / Q000819:agonists*; D018092:Kainic Acid Receptors / Q000819:agonists*; D016194:Receptors, N-Methyl-D-Aspartate / Q000819:agonists*; D013331:Strychnine / Q000494:pharmacology*; D014982:Xenopus laevis; D018350:alpha-Amino-3-hydroxy-5-methyl-4-isoxazolepropionic Acid / Q000494:pharmacology
D005998:Glycine; D007473:Ion Channels; D007608:Kainic Acid; D016202:N-Methylaspartate; D016318:Quisqualic Acid; D012333:RNA, Messenger; D018091:Receptors, AMPA; D018092:Kainic Acid Receptors; D016194:Receptors, N-Methyl-D-Aspartate; D013331:Strychnine; D018350:alpha-Amino-3-hydroxy-5-methyl-4-isoxazolepropionic Acid