ATP P2X receptors play little role in the maintenance of neuropathic hyperalgesia.

There is good evidence that ATP receptors play a role in nociception in the periphery. We sought evidence that they contribute to neuropathic hyperalgesia. We carried out a partial ligation of the sciatic nerve in rats to induce nerve injury and neuropathic hyperalgesia. Intrathecal injection of suramin (a P2 purinoceptor antagonist) provided minor alleviation of thermal hyperalgesia, while PPADS (a selective P2X receptor antagonist) had no effect. Both suramin and PPADS caused abnormal behavior including aggressiveness and subsequent hyporeactivity and immobility. P2X receptors in the spinal cord do not appear to play a significant role in the maintenance of thermal hyperalgesia. However, P2X receptors may play an important role in the control of behaviour.