Puerarin blocks the signaling transmission mediated by P2X3 in SG and DRG to relieve myocardial ischemic damage

P2X3 receptors in stellate ganglia (SG) and cervical dorsal root ganglia (DRG) neurons are involved in sympathoexcitatory reflex induced by myocardial ischemic damage. Puerarin, a major active ingredient extracted from the traditional Chinese plant medicine Ge-gen, has been widely used in treatment of myocardial and cerebral ischemia. The present study is aimed to observe the effects of puerarin on the signaling transmission mediated by P2X3 receptor in SG and DRG after myocardial ischemic damage. Our results showed that systolic blood pressure and heart rate increased, and the expression levels of P2X3 mRNA and protein in SG and DRG were up-regulated after myocardial ischemic damage. Puerarin reduced systolic blood pressure and heart rate, relieved pain and decreased up-regulated expression of P2X3 mRNA and protein in SG and DRG after myocardial ischemia. Puerarin inhibited the up-regulated ATP-activated currents in DRG neurons after myocardial ischemia. Thus, puerarin can relieve myocardial ischemic damage through blocking the P2X3 signaling transmission and then depressed the aggravated sympathoexcitatory reflex.