P2X receptor-mediated excitation of nociceptive afferents in the normal and arthritic rat knee joint

摘要

We tested the hypothesis that functional P2X receptors are present on peripheral terminals of primary afferent articular nociceptors in the rat knee joint. Neural activity was recorded extracellularly from the medial articular nerve innervating the knee joint n rats anaesthetized with pentobarbitone. The selective P2X receptor agonist, αβmethylene ATP(αβmeATP), and the endogenous ligand, ATP, Caused a rapid short-lasting excitation of a sub-population of C and Aδnociceptive afferent nerves Innervating normal knee joints when injected intra-arterially or intra-articularly, and this effect was Antagonized by the non-selective P2 receptor antagonist PPADS.