MK-801 reduces non-noxious stimulus-evoked Fos-like immunoreactivity in the spinal cord of rats with chronic constriction nerve injury.
We investigated the role of N-methyl-D-aspartate (NMDA) receptors on non-noxious stimulus-induced pain by examining the effect of MK-801, a non-competitive NMDA receptor antagonist, on Fos-like immunoreactivity (FLI) in the spinal dorsal horn by non-noxious stimulation to rats with chronic constriction injury (CCI) of the sciatic nerve. In CCI rats that did not receive the non-noxious stimulus, FLI was significantly increased in laminae V/VI of the dorsal horn at the 7th and 14th days after surgery relative to sham rats. When CCI rats received non-noxious stimuli, rubbing the plantar of the hind paw, FLI in laminae I/II at the 14th day was significantly increased relative to CCI rats that did not receive the stimulation. In sham rats, the same stimulus significantly decreased FLI in laminae III/IV and V/VI at the 7th and 14th day. When MK-801 was administered intraperitoneally prior to non-noxious stimulation in CCI rats at the 14th day after surgery, the stimulus-induced FLI in laminae I/II in CCI rats was significantly reduced. This study indicates that NMDA receptor is involved in upregulating FLI in response to non-noxious stimulation of CCI rats.
Kosai
K
K
Department of Anesthesiology, Miyazaki Medical College, Kiyotake, Miyazaki 889-1692 , Japan.
Tateyama
S
S
Ikeda
T
T
Uno
T
T
Nishimori
T
T
Takasaki
M
M
D000818:Animals; D002452:Cell Count; D002908:Chronic Disease; D004195:Disease Models, Animal; D016291:Dizocilpine Maleate / Q000494:pharmacology*; D015536:Down-Regulation / Q000187:drug effects / Q000502:physiology*; D018691:Excitatory Amino Acid Antagonists / Q000494:pharmacology*; D007150:Immunohistochemistry; D008297:Male; D008465:Mechanoreceptors / Q000293:injuries / Q000378:metabolism / Q000473:pathology; D009408:Nerve Compression Syndromes / Q000378:metabolism / Q000473:pathology / Q000503:physiopathology; D009473:Neuronal Plasticity / Q000187:drug effects / Q000502:physiology; D017288:Pain Threshold / Q000187:drug effects / Q000502:physiology; D010523:Peripheral Nervous System Diseases / Q000378:metabolism* / Q000473:pathology / Q000503:physiopathology; D010812:Physical Stimulation; D020671:Posterior Horn Cells / Q000187:drug effects / Q000378:metabolism*; D016760:Proto-Oncogene Proteins c-fos / Q000378:metabolism*; D051381:Rats; D016194:Receptors, N-Methyl-D-Aspartate / Q000037:antagonists & inhibitors / Q000378:metabolism*; D014110:Touch / Q000187:drug effects / Q000502:physiology
D018691:Excitatory Amino Acid Antagonists; D016760:Proto-Oncogene Proteins c-fos; D016194:Receptors, N-Methyl-D-Aspartate; D016291:Dizocilpine Maleate