It is AMPA receptor, not kainate receptor, that contributes to the NBQX-induced antinociception in the spinal cord of rats.
Studies demonstrated that intrathecal 1,2,3,4-tetrahydro-6-nitro-2, 3-dioxo[f]quinoxaline-7-sulfonamide disodium (NBQX), an antagonist of AMPA/kainate receptors, induced antinociception in the spinal cord of rats. The present study demonstrated that the NBQX-induced increases in hindpaw withdrawal latencies (HWLs) were dose-dependently attenuated by intrathecal pretreatment of the AMPA receptor desensitization inhibitor, diazoxide. The effect was unrelated to the opening of K+ channels by diazoxide. On the other hand, intrathecal pretreatment of concanavalin A, which selectively inhibits the desensitization of kainate receptor, produced no significant influence on the NBQX-induced antinociception. The results suggest that the NBQX-induced antinociception was mediated by AMPA receptors, not by kainate receptors, in the spinal cord of rats.
Kong
Ling-Ling
LL
Laboratory of Neurobiology and National Key Laboratory of Biomembrane and Membrane Biotechnology, College of Life Sciences, Peking University, Beijing 100871, PR China.
Yu
Long-Chuan
LC
D000700:Analgesics; D000818:Animals; D003208:Concanavalin A / Q000494:pharmacology; D003981:Diazoxide / Q000037:antagonists & inhibitors / Q000494:pharmacology; D004305:Dose-Response Relationship, Drug; D018691:Excitatory Amino Acid Antagonists / Q000494:pharmacology*; D007278:Injections, Spinal; D008297:Male; D010147:Pain Measurement / Q000187:drug effects; D015221:Potassium Channels / Q000187:drug effects / Q000378:metabolism; D011810:Quinoxalines / Q000494:pharmacology*; D051381:Rats; D017208:Rats, Wistar; D018091:Receptors, AMPA / Q000037:antagonists & inhibitors / Q000502:physiology*; D018092:Kainic Acid Receptors / Q000037:antagonists & inhibitors / Q000502:physiology*; D013116:Spinal Cord / Q000187:drug effects*
D000700:Analgesics; D003208:Concanavalin A; D003981:Diazoxide; D018691:Excitatory Amino Acid Antagonists; D015221:Potassium Channels; D011810:Quinoxalines; D018091:Receptors, AMPA; D018092:Kainic Acid Receptors; C062865:2,3-dioxo-6-nitro-7-sulfamoylbenzo(f)quinoxaline