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Enflurane inhibits NMDA, AMPA, and kainate‐induced currents in Xenopus oocytes expressing mouse and human brain mRNA
Author(s) -
Un LieHuey,
Chen Longtang L.,
Harris R. Adron
Publication year - 1993
Publication title -
the faseb journal
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.709
H-Index - 277
eISSN - 1530-6860
pISSN - 0892-6638
DOI - 10.1096/fasebj.7.5.7681790
Subject(s) - kainate receptor , ampa receptor , enflurane , nmda receptor , xenopus , glutamate receptor , ionotropic effect , gabaa receptor , anesthetic , chemistry , pharmacology , kainic acid , receptor , biology , medicine , endocrinology , biophysics , anesthesia , biochemistry , isoflurane , gene , organic chemistry
Effects of enflurane, an inhalational anesthetic, on NMDA, AMPA, and kainate‐gated currents were examined in Xenopus laevis oocytes expressing mouse or human brain mRNA. In oocytes expressing mouse mRNA, enflurane at an anesthetic concentration (1.8 mM) inhibited the NMDA‐, AMPA‐, and kainate‐induced currents by 29–40%, 30–33%, and 20–27%, respectively, suggesting that all three glutamate ionotropic receptors are susceptible to suppression by inhalational anesthetics. Furthermore, inhibition by enflurane was independent of the concentrations of the agonists (NMDA, AMPA, and kainate) or the NMDA‐coagonist (glycine). This suggests that enflurane inhibition does not result from a competitive interaction at glutamate or glycine binding sites. Enflurane also suppressed the oscillation and apparent desensitization of NMDA currents, suggesting an inhibition of Ca 2+ influx through the NMDA channel. In oocytes expressing human brain mRNA, only kainate produced observable currents. Kainate currents of human channels were smaller in size than those of the mouse; however, the kainate concentration‐response curve and percent inhibition (27–29%) by enflurane were similar for mice and humans. The results suggest that human and mouse kainate receptors have similar pharmacological characteristics.— Lin, L.‐H., Chen, L. L., Harris, R. A. Enflurane inhibits NMDA, AMPA, and kainateinduced currents in Xenopus oocytes expressing mouse and human brain mRNA. FASEB J. 7: 479‐485; 1993.