Electroacupuncture pretreatment improves myocardial ischemia-reperfusion injury through CRH neurons in the paraventricular nucleus of the hypothalamus mediated sympathetic nervous

Aim: Myocardial ischemia-reperfusion causes further aggravation of myocardial injury and increases the risk of death. Our previous studies found that paraventricular nucleus of hypothalamus (PVN) plays a crucial role in the improvement of myocardial ischemia-reperfusion injury (MIRI) by electroacupuncture (EA) pretreatment, but the mechanism of its action is still unclear.CRH neurons have a phase-concentrated expression in the PVN, but whether it is involved in the improvement of MIRI by EA pretreatment needs to be further investigated. Meanwhile, a large number of studies have shown that changes in sympathetic innervation and activity are associated with many cardiac diseases. The aim of this study was to investigate whether EA pretreatment improve MIRI through PVNCRH neurons mediated sympathetic nervous. Main methods: Through immunofluorescence, fiber-optic recording, chemical genetics and other methods, echocardiography, myocardial infarction area, sympathetic nerve discharge and other related indexes were detected to observe the effect of EA pretreatment on cardiac function. Key findings: The results showed that CRH neurons in the PVN region of the rat brain in the MIRI model had increased numbers of co-labeling with c-Fos, enhanced activity, and increased frequency of sympathetic discharges, whereas EA pretreatment reversed this change. Meanwhile, inhibition of PVNCRH had a protective effect on MIRI similar to that of EA pretreatment, which was counteracted by activation of PVNCRH neurons. Significance: EA pretreatment inhibits PVNCRH neurons and improves MIRI by inhibiting sympathetic nerves, providing a new direction of thinking for elucidating the mechanism of action of acupuncture in the treatment of cardiovascular diseases.