Increased cold allodynia following intrathecal N-methyl-D-aspartate in rats with a mononeuropathy.
NMDA receptors are involved in the modulation of neuropathic pain behavior and central sensitization. In vivo, this is mostly demonstrated by the use of specific antagonists such as MK801. Because studies evaluating the direct impact of spinal NMDA in neuropathic pain models are lacking, we performed a series of experiments to study the role of spinal NMDA injection on existing cold allodynia, as a measurement of neuropathic pain behavior in rodents. Intrathecal injection of NMDA resulted in an enhanced neuropathic pain behavior in CCI rats on a cold plate. The activity was present from a dose of 5 ng/rat onward and could selectively be reversed by intraperitoneal injections of doses of > or = 0.01 mg/kg MK801. These results support the regulatory role of NMDA receptors in the hypersensitivity to cold observed in neuropathic pain behavior in rodents.
Vissers
Kris C
KC
Multidisciplinary Pain Center, Ziekenhuis Oost-Limburg, Campus André Dumont, Stalenstraat 2, 3600 Genk, Belgium. kris.vissers@skynet.be
Hoffmann
Vincent L
VL
Adriaensen
Hugo F
HF
Heylen
Rene J
RJ
Meert
Theo F
TF
D000818:Animals; D003080:Cold Temperature; D004195:Disease Models, Animal; D016291:Dizocilpine Maleate / Q000494:pharmacology; D004305:Dose-Response Relationship, Drug; D007278:Injections, Spinal; D008297:Male; D016202:N-Methylaspartate / Q000494:pharmacology*; D010146:Pain / Q000209:etiology* / Q000378:metabolism; D010147:Pain Measurement; D051381:Rats; D017207:Rats, Sprague-Dawley; D016194:Receptors, N-Methyl-D-Aspartate / Q000037:antagonists & inhibitors; D020426:Sciatic Neuropathy / Q000150:complications*
D016194:Receptors, N-Methyl-D-Aspartate; D016202:N-Methylaspartate; D016291:Dizocilpine Maleate