[ATP receptors in pain].
Extracellular ATP has been known to activate sensory neurons via the ATP-gated ion channels P2X receptors, leading to the proposal that the P2X receptors may play a role in signal transduction of pain from the peripheral site to the spinal cord in vivo. P2X3 receptors are expressed in capsaicin-sensitive small-sized dorsal root ganglion (DRG) neurons, and they are involved in the generation of rapidly desensitizing inward current and evoking nocifensive behavior and thermal hyperalgesia. Heteromeric P2X2/3 (P2X2 and P2X3) receptor is expressed in capsaicin-insensitive primary afferent fibers, and its activation leads to the generation of slow desensitizing currents and induction of mechanical allodynia. In addition, accumulating information suggests the involvement of G protein-coupled ATP receptors in the modulation of the generation and transmission of pain.
Tsuda
M
M
Neuropharmacology Section, Division of Pharmacology, National Institute of Health Sciences, 1-18-1 Kamiyoga, Setagaya, Tokyo 158-8501, Japan.
Koizumi
S
S
Inoue
K
K
D000255:Adenosine Triphosphate / Q000502:physiology; D000818:Animals; D002211:Capsaicin / Q000378:metabolism; D004594:Electrophysiology; D005727:Ganglia, Spinal / Q000378:metabolism; D006801:Humans; D006930:Hyperalgesia; D009619:Nociceptors / Q000502:physiology; D010146:Pain / Q000503:physiopathology*; D018048:Receptors, Purinergic P2 / Q000502:physiology*; D058476:Receptors, Purinergic P2X2; D058477:Receptors, Purinergic P2X3; D015398:Signal Transduction / Q000502:physiology
C546401:P2RX2 protein, human; C546407:P2RX3 protein, human; D018048:Receptors, Purinergic P2; D058476:Receptors, Purinergic P2X2; D058477:Receptors, Purinergic P2X3; D000255:Adenosine Triphosphate; D002211:Capsaicin