Biao and Ben Acupoints Regulate Mitochondrial Function Through P2X Receptor to Improve Myocardial Ischemia

Ischemic heart disease is a common disease in older surgical patients. The current treatments for myocardial ischemia mainly restore blood flow to an extent, but reperfusion inevitably causes reperfusion injury. Single-point acupuncture and moxibustion can strengthen the body's resistance and eliminate pathogenic factors, but medical practitioners haven't considered matching acupoints in treatments for myocardial ischemia.

The study intended to examine the effects of electroacupuncture using the Biao and Ben acupoints on the structure and function of myocardial mitochondria, the changes in the expression of related proteins, and the intraoperative circulation of rats with myocardial ischemia and to provide a theoretical basis for the clinical use of the Biao-Ben acupoints.

The research team performed an animal study.

The study took place in Lanzhou Maternal and Child Health Hospital.

The animals were 84 male Sprague-Dawley (SD) rats, weighing 160-220 g.

The research team divided the rats into seven groups, with 12 rats in each group. The study evaluated two types of interventions: (1) zinc chloride (ZnCl2) and (2) electroacupuncture. The team used two versions of each type of intervention, for four groups in total: (1) a low dose of ZnCl2, the low-dose ZnCl2 group; (2) a high dose of ZnCl2, the high-dose ZnCl2 group; (3) electroacupuncture using a single acupoint, the Neiguan point, for the Neiguan group; and (4) electroacupuncture using three acupoints, the Neiguan point and the Biao and Ben points, for the Biao-Ben group. The study included three control groups-the control group, a positive control group; the sham group, a ZnCl2 control group; and the model group, a negative control group. The team collectively called five of the groups the operation group, which included all four intervention groups and the model group, in which the team induced ischemic heart disease.

The research team measured: (1) the relative changes in the mitochondrial ultrastructure of the rat cardiomyocytes for each group using a laser confocal, fluorescent indicator assay to detect the concentration of calcium(2+) [Ca2+] in the cytoplasm of cardiomyocytes; (2) the content of adenosine triphosphate (ATP) in myocardial tissue using ATP-detection technology; (3) mitochondrial activity using the fluorescent probe method; and (4) the protein levels of P2X purinoceptor 7 (P2X7) and mitochondria-related oxidative stress factors on the myocardial cell membrane using Western blot technology. The team monitored the physiology of the rats in each group.

Compared with the model group, the two ZnCl2 groups and the two electroacupuncture groups showed: (1) a significantly improved mitochondrial structure and function of the ischemic cardiomyocytes, (2) a significant increase in the mitochondrial activity, (3) a significant increase in the permeability of the membrane and thus an increase the concentration of Ca2+ in the cytoplasm, (4) a significant increase in the content of ATP inside and outside the myocardium, (5) at the same time, a significant reduction in the protein levels of the P2X7 receptors on the myocardial cell membrane and the peroxisome proliferator-activated receptor gamma coactivator 1-alpha (PGC-1α) and manganese superoxide dismutase (MnSOD) in mitochondria, and (6) a significant reduction in the protein levels of nitric oxide (NO) and cytochrome C (CytC).

The Biao and Ben electroacupuncture can improve the structure and function of mitochondria in the myocardial cells of rats with myocardial ischemia, reduce the expression levels of the P2X7 receptor, NO, and CytC proteins, increase the expression levels of PGC-1α and MnSOD, and improve the intraoperative circulation, thus having a positive effect on myocardial ischemia.