ATP Receptor Involvement in Neuropathic Pain

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ATP Receptor Involvement in Neuropathic Pain

http://www.medicalnewstoday.com/articles/100341.php

Kimiko Kobayashi, Hiroki Yamanaka, Tetsuo Fukuoka, Yi Dai, Koichi

Obata, and Koichi Noguchi

Nerve injury often leads to neuropathic pain, such as thermal

hyperalgesia and mechanical allodynia, a painful response to normally

innocuous stimuli. Microglia are thought to play a prominent role in

neuropathic pain, in part by releasing inflammatory molecules.

Phosphorylation of p38 mitogen-activated protein kinase (MAPK) in

microglia also appears to be involved. Kobayashi et al. now suggest

that release of ATP from injured nerves may be a first step in the

development of neuropathic pain. They show that after nerve injury,

the levels of an ADP/ATP receptor, P2Y12, increased in microglia in

the spinal cord. Both an antagonist of and antisense oligonucleotides

against P2Y12 significantly reduced mechanical allodynia and thermal

hyperalgesia following nerve injury, and they also prevented the

increase in p38 phosphorylation that normally follows injury. In

contrast, a P2Y12 agonist induced mechanical allodynia and thermal

hyperalgesia, both of which were attenuated by coadministration of a

p38 MAPK inhibitor.