Role of alpha-amino-3-hydroxy-5-methyl-4-isoxazolepropionate (AMPA) receptor subunit GluR1 in spinal dorsal horn in inflammatory nociception and neuropathic nociception in rat.
The present study aims to investigate changes of spinal cord AMPA receptor GluR1 and its phosphorylation in inflammatory and neuropathic pain. Complete Freund's adjuvant (CFA) injection into the hind paw produced inflammatory thermal hyperalgesia that was assessed by decreased response latency to radiant heat; spinal nerve ligation (SNL) was used to induce mechanical allodynia that was evaluated with von Frey hairs. By method of Western blot, expression of GluR1 (the main subunit of the AMPA receptor) and its phosphorylated forms at serine 845 (pGluR1-Ser845) and at serine 831 (pGluR1-Ser831) in the spinal dorsal horn was observed. It was found that the expression of pGluR1-Ser845 and pGluR1-Ser831 increased significantly at 1 h after CFA injection, reached peak at 4 h and returned to the normal control level at 24 h, while no significant change was detected in GluR1 itself. In contrast, neither GluR1 nor pGluR1 showed any significant change in rats following SNL. These results suggest that phosphorylated GluR1 (pGluR1-Ser845 and pGluR1-Ser831) might play a role in the induction of inflammatory but not neuropathic pain.
Lu
Yue
Y
Neuroscience Research Institute, Peking University, 38 Xueyuan Road, Beijing 100083, China.
Sun
Yan-Ni
YN
Wu
Xi
X
Sun
Qian
Q
Liu
Feng-Yu
FY
Xing
Guo-Gang
GG
Wan
You
Y
D000595:Amino Acid Sequence / Q000502:physiology; D000818:Animals; D004195:Disease Models, Animal; D005620:Freund's Adjuvant; D006930:Hyperalgesia / Q000139:chemically induced / Q000378:metabolism / Q000503:physiopathology; D007249:Inflammation / Q000378:metabolism* / Q000503:physiopathology; D008026:Ligation; D008297:Male; D009437:Neuralgia / Q000378:metabolism* / Q000503:physiopathology; D009619:Nociceptors / Q000378:metabolism* / Q000503:physiopathology; D017288:Pain Threshold / Q000502:physiology; D010523:Peripheral Nervous System Diseases / Q000378:metabolism* / Q000503:physiopathology; D010766:Phosphorylation; D010812:Physical Stimulation; D020671:Posterior Horn Cells / Q000378:metabolism*; D051381:Rats; D017207:Rats, Sprague-Dawley; D011930:Reaction Time / Q000502:physiology; D018091:Receptors, AMPA / Q000737:chemistry / Q000378:metabolism*; D012694:Serine / Q000378:metabolism; D013697:Thermosensing / Q000502:physiology
D005620:Freund's Adjuvant; D018091:Receptors, AMPA; D012694:Serine