Diverse modulation by systemic lidocaine of iontophoretic NMDA and quisqualic acid induced excitations on rat dorsal horn neurons.
The effects of systemic lidocaine (3-4 mg/kg) on the responses of 60 wide dynamic range neurons (WDR) to iontophoretically applied N-methyl-D-aspartic acid (NMDA) and quisqualic acid (QUIS) were studied in anesthetized, paralysed rats. The results show that lidocaine induced (i) potentiation of the NMDA excitation, reversible by 7-chloro-kynurenate (7-Cl-KYNA), a selective antagonist of the glycine binding site on the NMDA receptor; (ii) reduction of the QUIS excitation, reversible by strychnine (STRYCH), a glycine antagonist at its receptor. These findings, supporting a glycine-like action of lidocaine, are discussed together with data on the role of excitatory amino acids (EAAs) and the analgesic effect of lidocaine on neuropathic pain.
Biella
G
G
Istituto di Neuroscienze e Bioimmagini, CNR, Milan, Italy.
Lacerenza
M
M
Marchettini
P
P
Sotgiu
M L
ML
D000818:Animals; D004357:Drug Synergism; D005998:Glycine / Q000502:physiology*; D007275:Injections, Intravenous; D007478:Iontophoresis; D007736:Kynurenic Acid / Q000031:analogs & derivatives / Q000494:pharmacology; D008012:Lidocaine / Q000008:administration & dosage / Q000494:pharmacology*; D008297:Male; D016202:N-Methylaspartate / Q000008:administration & dosage / Q000494:pharmacology*; D016318:Quisqualic Acid / Q000008:administration & dosage / Q000494:pharmacology*; D051381:Rats; D017208:Rats, Wistar; D018009:Receptors, Glycine / Q000187:drug effects / Q000502:physiology; D016194:Receptors, N-Methyl-D-Aspartate / Q000037:antagonists & inhibitors / Q000187:drug effects; D013331:Strychnine / Q000494:pharmacology
D018009:Receptors, Glycine; D016194:Receptors, N-Methyl-D-Aspartate; D016202:N-Methylaspartate; D016318:Quisqualic Acid; D008012:Lidocaine; D007736:Kynurenic Acid; D013331:Strychnine; C057013:7-chlorokynurenic acid; D005998:Glycine