P2X Receptor Antibodies for Pain Research Explorer Kit

P2X receptors comprise a family of seven members (P2X1-7) of extracellular ATP-gated cation channels. They are expressed in somatic and nervous tissues. These receptors have been implicated in a variety of neurological, inflammatory and cardiovascular diseases¹.

P2X receptors consist of two transmembrane subunits with a large extracellular domain, which shows conserved cysteine residues in all members of the family. P2X3 is the focus of pain pathways research due to its selective expression in nociceptive neurons. Interestingly, expression of P2X3 is species specific. While the rat form seems to be sensory neuron specific, in mice and human there is a broader pattern of expression, with some evidence for expression in cardiac muscle and motor neurons.

Immunocytochemistry studies have indicated an upregulation of P2X3 receptors in both DRG and dorsal horn neurons following neuropathic injury. ATP and thus P2X receptors play a significant role in pain pathways. Intrathecal administration of a P2X agonist produces a dose-dependent thermal hyperalgesic response which is blocked by P2X antagonists. ATP agonists do not cause a similar response in P2X1 receptors, suggesting it is not involved in this effect. Animals injected with P2X agonists exhibit overt nociceptive behaviour such as hindpaw lifting and licking².

P2X receptors have also been implicated as having a major role in visceral sensory function and have been put forward as potential therapeutic targets for visceral pain such as IBD and IBS. ATP released from epithelium lining cells upon distention of hollow organs acts on the P2X receptors which relay the information to the CNS and subsequently cause pain³.