title: Induction of the P2X7 receptor in spinal microglia in a neuropathic pain model.
abstract: Peripheral nerve injury causes a progressive series of morphological changes in spinal microglia, and extracellular ATP stimulates proliferation of microglia and may be involved in neuropathic pain. We defined the precise expression of P2X7 in the spinal cord following peripheral nerve injury. We found that both P2X7 mRNA and protein increased in the spinal cord, with a peak at 7d after injury. Double labeling studies revealed that cells expressing increased P2X7 mRNA and protein after nerve injury were predominantly microglia in dorsal horn. Pharmacological blockades by intrathecal administration of a P2X7 antagonist (A 438079 hydrochloride) suppressed the development of mechanical hypersensitivity. We present distinct evidence that increases in the number of P2X7 receptors in spinal microglia may play an important role in neuropathic pain.
authors.affiliation: Department of Anatomy and Neuroscience, Hyogo College of Medicine, 1-1 Mukogawa-cho, Nishinomiya, Hyogo 663-8501, Japan.
authors.forename: Kimiko
authors.initials: K
authors.lastname: Kobayashi
authors.forename: Emiko
authors.initials: E
authors.lastname: Takahashi
authors.forename: Yasuko
authors.initials: Y
authors.lastname: Miyagawa
authors.forename: Hiroki
authors.initials: H
authors.lastname: Yamanaka
authors.forename: Koichi
authors.initials: K
authors.lastname: Noguchi
mesh_terms: D000818:Animals; D004195:Disease Models, Animal; D015870:Gene Expression; D006801:Humans; D006930:Hyperalgesia / Q000188:drug therapy; D008297:Male; D017628:Microglia / Q000378:metabolism*; D009437:Neuralgia / Q000378:metabolism*; D059348:Peripheral Nerve Injuries / Q000378:metabolism; D058920:Purinergic P2X Receptor Antagonists / Q000494:pharmacology; D011725:Pyridines / Q000494:pharmacology; D051381:Rats; D017207:Rats, Sprague-Dawley; D058486:Receptors, Purinergic P2X7 / Q000096:biosynthesis*; D013116:Spinal Cord / Q000378:metabolism*; D013777:Tetrazoles / Q000494:pharmacology; D014110:Touch / Q000187:drug effects
chemical_list: C523668:3-(5-(2,3-dichlorophenyl)-1H-tetrazol-1-yl)methylpyridine; D058920:Purinergic P2X Receptor Antagonists; D011725:Pyridines; D058486:Receptors, Purinergic P2X7; D013777:Tetrazoles