P2RX3 and peripheral arterial disease: Our previous studies have demonstrated that (1) compared with the resting status, the interstitial ATP concentration is enhanced when the muscle is active (Li et al., 2005), (2) the protein levels of the purinergic P2X3 expression are increased in the DRG of rats with 24–72 h of femoral artery occlusion (Liu et al., 2011), and (3) the BP response to stimulation of P2X3 by αβ-methylene ATP (αβ-me ATP; P2X3 agonist) in the afferent nerves is amplified in rats with simulated PAD (Liu et al., 2011; Xing et al., 2013).