Involvement of N-methyl-D-aspartate-type glutamate receptor epsilon1 and epsilon4 subunits in tonic inflammatory pain and neuropathic pain.
N-methyl-D-aspartate receptors play an important role in nociceptive transmissions in various types of pain. In this study, we investigated the pain-related response in mice lacking the N-methyl-D-aspartate-type glutamate receptor epsilon1 or epsilon4 subunit in the formalin test and in the partial sciatic nerve ligation-induced neuropathic pain model. The second tonic inflammatory phase response in the formalin test was significantly reduced in glutamate receptor epsilon1 knockout epsilon1(-/-) mice, but not in glutamate receptor epsilon4(-/-) when compared with wild-type mice. In the partial sciatic nerve ligation model, glutamate receptor epsilon1(-/-) mice exhibited no difference in mechanical allodynia compared with wild-type mice. Glutamate receptor epsilon4(-/-) mice, however, failed to develop allodynia after the nerve ligation. These results suggest that glutamate receptor epsilon1 and epsilon4 subunits are involved in tonic inflammatory pain and neuropathic allodynia, respectively.
Hizue
Masanori
M
Discovery Biology Research, Nagoya Laboratories, Pfizer Global Research and Development, Pfizer Inc., Aichi, Japan. Masanori.Hizue@pfizer.com
Pang
Chang-Hong
CH
Yokoyama
Masayuki
M
D000818:Animals; D005557:Formaldehyde; D007249:Inflammation / Q000150:complications / Q000503:physiopathology*; D008026:Ligation; D051379:Mice; D008810:Mice, Inbred C57BL; D018345:Mice, Knockout; D010146:Pain / Q000209:etiology / Q000503:physiopathology*; D010147:Pain Measurement / Q000187:drug effects; D010523:Peripheral Nervous System Diseases / Q000150:complications / Q000503:physiopathology*; D010812:Physical Stimulation; D016194:Receptors, N-Methyl-D-Aspartate / Q000235:genetics / Q000502:physiology*; D020426:Sciatic Neuropathy / Q000503:physiopathology
C120997:NR2A NMDA receptor; D016194:Receptors, N-Methyl-D-Aspartate; D005557:Formaldehyde