Effects of Electroacupuncture at Neiguan(PC 6) on Expression of P2X_3 Receptor of Myocardium in Myocardial Pain Rats

Objective To investigate the effects of electroacupunctur at Neiguan on the expression of P2X3 receptor protein of myocardium and hypothalamus in myocardial pain rats induced by ISO. Methods Sprague-Dawly weighing 180-250 g rats were used in experiment. Rats were injected subcutaneously with ISO for 14 consecutive days to induce myocardial pain model. Rats were randomly divided into normal group( N group),control group treated with saline( C group),myocardial pain group( M group),electroacupuncture-treated myocardial pain group( E group). The behavioral and weight changes were observed after rats were executed,hematoxylin and eosin staining was used to observed the changes of myocardial tissue and the P2X3 receptor and β-actin protein expression in myocardium were determined by Western blotting. Results Weight gain in the C group grew less than the N group,and had statistical significance( P 0. 01). Weight gain in the M and E group grew less than the N and C group( P 0. 01). Weight gain in the E group was significantly higher the M group( P 0. 01). The behavioral changes in the M and E group were higher than the N group and the C group( P 0. 01). The behavioral changes in the E group was less than the M group( P 0. 01). The cardiac tissues from N and the C group showed thin and compact arrangement. The cardiac tissues from M group showed severe atrophy,hypertrophy and proliferation of fiber connective tissue. The cardiac tissues from E showed slight atrophy and vicarious hypertrophy. The P2X3 receptor protein expression of myocardium in M group was significantly higher than that in N group and C group( P 0. 01). The P2X3 receptor protein expressions of myocardium in E group was significantly lower than that in M group( P 0. 01). The P2X3 receptor protein expression of hypothalamus in M group was significantly higher than that in N group and C group( P 0.01). The P2X3 receptor protein expressions of hypothalamus in E group was significantly lower than that in M group( P 0. 01). Conclusion The P2X3 receptor protein expression of myocardium and hypothalamus in M group were significantly higher than that in N group and C group.The P2X3 receptor protein expression of myocardium and hypothalamus in E group was significantly lower than that in M group. Acupuncture analgesia by Neiguan possibly realizes its action on inhibiting the expression of the P2X3 receptor protein.