title: Philanthotoxin blocks quisqualate-, AMPA- and kainate-, but not NMDA-, induced excitation of rat brainstem neurones in vivo.
abstract: 1. The effect of electrophoretic ejection of philanthotoxin (the polyamine toxin, from the Egyptian digger wasp) was tested on responses of brainstem and spinal neurones in the pentobarbitone-anaesthetized rat to excitatory amino acids. 2. Philanthotoxin caused a dose-dependent reduction of responses to quisqualate, alpha-amino-3-hydroxy-5-phenyl-4-isoxazolepropionate (AMPA) and kainate with little effect on those to N-methyl-D-aspartate (NMDA). 3. The time-course of this antagonist action was slow. In particular the rate of recovery was dependent on frequency of ejection of the agonist. This agonist-dependent recovery suggests that philanthotoxin has a channel blocking mode of action on mammalian central neurones.
authors.affiliation: Department of Veterinary Basic Sciences, Royal Veterinary College, London.
authors.forename: M G
authors.initials: MG
authors.lastname: Jones
authors.forename: N A
authors.initials: NA
authors.lastname: Anis
authors.forename: D
authors.initials: D
authors.lastname: Lodge
mesh_terms: D000200:Action Potentials / Q000187:drug effects; D000818:Animals; D001933:Brain Stem / Q000166:cytology* / Q000187:drug effects; D005260:Female; D007051:Ibotenic Acid / Q000031:analogs & derivatives* / Q000037:antagonists & inhibitors; D007608:Kainic Acid / Q000037:antagonists & inhibitors*; D016202:N-Methylaspartate / Q000037:antagonists & inhibitors*; D009474:Neurons / Q000187:drug effects*; D011073:Polyamines; D016318:Quisqualic Acid / Q000037:antagonists & inhibitors*; D051381:Rats; D011919:Rats, Inbred Strains; D014862:Wasp Venoms / Q000494:pharmacology*; D018350:alpha-Amino-3-hydroxy-5-methyl-4-isoxazolepropionic Acid
chemical_list: D011073:Polyamines; D014862:Wasp Venoms; D007051:Ibotenic Acid; D016202:N-Methylaspartate; C034092:delta-philanthotoxin; D018350:alpha-Amino-3-hydroxy-5-methyl-4-isoxazolepropionic Acid; D016318:Quisqualic Acid; D007608:Kainic Acid