A-740003 [N-(1-{[(cyanoimino)(5-quinolinylamino) methyl]amino}-2,2-dimethylpropyl)-2-(3,4-dimethoxyphenyl)acetamide], a novel and selective P2X7 receptor antagonist, dose-dependently reduces neuropathic pain in the rat.
ATP-sensitive P2X(7) receptors are localized on cells of immunological origin including glial cells in the central nervous system. Activation of P2X(7) receptors leads to rapid changes in intracellular calcium concentrations, release of the proinflammatory cytokine interleukin-1beta (IL-1beta), and following prolonged agonist exposure, cytolytic plasma membrane pore formation. P2X(7) knockout mice show reduced inflammation as well as decreased nociceptive sensitivity following peripheral nerve injury. A-740003 (N-(1-{[(cyanoimino)(5-quinolinylamino) methyl] amino}-2,2-dimethylpropyl)-2-(3,4-dimethoxyphenyl)acetamide) is a novel competitive antagonist of P2X(7) receptors (IC(50) values = 40 nM for human and 18 nM for rat) as measured by agonist-stimulated changes in intracellular calcium concentrations. A-740003 showed weak or no activity (IC(50) > 10 muM) at other P2 receptors and an array of other neurotransmitter and peptide receptors, ion channels, reuptake sites, and enzymes. A-740003 potently blocked agonist-evoked IL-1beta release (IC(50) = 156 nM) and pore formation (IC(50) = 92 nM) in differentiated human THP-1 cells. Systemic administration of A-740003 produced dose-dependent antinociception in a spinal nerve ligation model (ED(50) = 19 mg/kg i.p.) in the rat. A-740003 also attenuated tactile allodynia in two other models of neuropathic pain, chronic constriction injury of the sciatic nerve and vincristine-induced neuropathy. In addition, A-740003 effectively reduced thermal hyperalgesia observed following intraplantar administration of carrageenan or complete Freund's adjuvant (ED(50) = 38-54 mg/kg i.p.). A-740003 was ineffective in attenuating acute thermal nociception in normal rats and did not alter motor performance at analgesic doses. These data demonstrate that selective blockade of P2X(7) receptors in vivo produces significant antinociception in animal models of neuropathic and inflammatory pain.
Honore
Prisca
P
Neuroscience Research, Global Pharmaceutical Research and Development, Abbott Laboratories, Abbott Park, Illinois 60064, USA.
Donnelly-Roberts
Diana
D
Namovic
Marian T
MT
Hsieh
Gin
G
Zhu
Chang Z
CZ
Mikusa
Joe P
JP
Hernandez
Gricelda
G
Zhong
Chengmin
C
Gauvin
Donna M
DM
Chandran
Prasant
P
Harris
Richard
R
Medrano
Arturo Perez
AP
Carroll
William
W
Marsh
Kennan
K
Sullivan
James P
JP
Faltynek
Connie R
CR
Jarvis
Michael F
MF
D000081:Acetamides / Q000494:pharmacology*; D000700:Analgesics; D000818:Animals; D000972:Antineoplastic Agents, Phytogenic / Q000633:toxicity; D002118:Calcium / Q000378:metabolism; D002460:Cell Line; D004396:Coloring Agents; D004305:Dose-Response Relationship, Drug; D004487:Edema / Q000139:chemically induced / Q000188:drug therapy; D005620:Freund's Adjuvant / Q000494:pharmacology; D006801:Humans; D006930:Hyperalgesia / Q000139:chemically induced / Q000188:drug therapy; D007249:Inflammation / Q000139:chemically induced / Q000150:complications / Q000188:drug therapy; D053583:Interleukin-1beta / Q000378:metabolism; D008297:Male; D009043:Motor Activity / Q000187:drug effects; D009619:Nociceptors / Q000187:drug effects; D010146:Pain / Q000188:drug therapy* / Q000209:etiology*; D010523:Peripheral Nervous System Diseases / Q000150:complications*; D004856:Postural Balance / Q000187:drug effects; D058919:Purinergic P2 Receptor Antagonists; D011804:Quinolines / Q000494:pharmacology*; D051381:Rats; D017207:Rats, Sprague-Dawley; D058486:Receptors, Purinergic P2X7; D020426:Sciatic Neuropathy / Q000517:prevention & control; D013127:Spinal Nerves / Q000293:injuries; D014750:Vincristine / Q000633:toxicity
C515928:(N-(1-(((cyanoimino)(5-quinolinylamino) methyl) amino)-2,2-dimethylpropyl)-2-(3,4-dimethoxyphenyl)acetamide); D000081:Acetamides; D000700:Analgesics; D000972:Antineoplastic Agents, Phytogenic; D004396:Coloring Agents; D053583:Interleukin-1beta; C546468:P2RX7 protein, human; C546469:P2rx7 protein, mouse; C546470:P2rx7 protein, rat; D058919:Purinergic P2 Receptor Antagonists; D011804:Quinolines; D058486:Receptors, Purinergic P2X7; D014750:Vincristine; D005620:Freund's Adjuvant; D002118:Calcium