The effects and interaction of ketamine and magnesium on NMDA receptors expressed in xenopus oocytes
- VernacularTitle:镁和氯胺酮对表达于Xenopus卵细胞的N-甲基-D-天冬氨酸受体的影响及其相互作用
- Author:
Hongtao LIU
;
Weihua LIU
;
Junke WANG
- Publication Type:Journal Article
- From:
Chinese Journal of Anesthesiology
2001;21(5):295-298
- CountryChina
- Language:Chinese
-
Abstract:
Objective It has been shown that ketamine and magnesium used in combination provide more effective analgesia than either drug alone. The purpose of this study was to investigate the effects and interaction of the two drugs on recombinantly expressed NMDA receptors. Methods Xenopus oocytes expressing NR1/NR2A or NR1/NR2B glutamate receptors were stimulated with glutamate/glycine and studied at a holding potential of -70mV using two electrode voltage clamp. The effects of magnesium and s ( + )-ketamine alone or in combination on NMDA signaling were determined. Results Magnesium and s( + )-ketamine alone inhibited NMDA receptors non-competitively. IC50s of magnesium were (4.2 ± 1.2)×10-4mol/L and (6.3 ± 2.4) × 10-4 mol/L on NR1/NR2A and NR1/NR2B, while IC50s of s( + )-ketamine on NR1/NR2A and NR1/NR2B were (4.1 ± 2.5) × 10-6 mol/L and (3.0 ± 0.3 ) × 10-6 mol/Lrespectively. Magnesium and s( + )-ketamine used in combination decreased IC50s more than 90% at both receptors. Isobolographic analysis demonstrated superadditive interactions. Conclusions s( + )-ketarnine and magnesium inhibit responses of recombinantly expressed NMDA recptors non-competitively, and the combinations of the two drugs produces a synergistic effect.
