Article date: July 1994
By: Boris A. Chizh, Michael J. Cumberbatch, P. Max Headley, in Volume 112, Issue 3, pages 843-846
The effects of intravenous administration of two α‐amino‐3‐hydroxy‐5‐methylisoxazole‐4‐propionic acid (AMPA) antagonists were studied on responses of single neurones to iontophoretically applied excitatory amino acids. The tests were performed on spinal neurones in α‐chloralose anaesthetized, spinalized rats.
Both the quinoxaline, NBQX (2–16 mg kg−1) and the 2,3‐benzodiazepine, GYKI 53655 (2–8 mg kg−1) dose‐dependently decreased responses to AMPA.
Both compounds were short acting, with half‐recovery times of 15 min for NBQX and 7 min for GYKI 53655.
The selectivity for responses to AMPA over those to N‐methyl‐d‐aspartate (NMDA) was significantly poorer for systemic NBQX than for either systemic GYKI 53655 or iontophoretic NBQX, suggesting that systemic NBQX may be converted to a less selective metabolite.
GYKI 53655 is therefore likely to be a more valuable tool than NBQX for the study of AMPA receptor‐mediated processes in vivo.
The effects of intravenous administration of two α‐amino‐3‐hydroxy‐5‐methylisoxazole‐4‐propionic acid (AMPA) antagonists were studied on responses of single neurones to iontophoretically applied excitatory amino acids. The tests were performed on spinal neurones in α‐chloralose anaesthetized, spinalized rats.
Both the quinoxaline, NBQX (2–16 mg kg−1) and the 2,3‐benzodiazepine, GYKI 53655 (2–8 mg kg−1) dose‐dependently decreased responses to AMPA.
Both compounds were short acting, with half‐recovery times of 15 min for NBQX and 7 min for GYKI 53655.
The selectivity for responses to AMPA over those to N‐methyl‐d‐aspartate (NMDA) was significantly poorer for systemic NBQX than for either systemic GYKI 53655 or iontophoretic NBQX, suggesting that systemic NBQX may be converted to a less selective metabolite.
GYKI 53655 is therefore likely to be a more valuable tool than NBQX for the study of AMPA receptor‐mediated processes in vivo.
DOI: 10.1111/j.1476-5381.1994.tb13156.x
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