[Protective effect of "neiguan" (PC 6)-electroacupuncture preconditioning on the myocardium in myocardial ischemia/reperfusion rats].

OBJECTIVE

To investigate the effects of "Neiguan" (PC 6)-electroacupunture (EA) preconditioning on the myocardium and its mast cells in myocardial ischemia/reperfusion (MI/R) rats.

METHODS

Eighteen male SD rats were randomly assigned to sham group, model (IR) group and EA group (n=6/ group). MI/R model was established by occlusion of the descending anterior branch of the coronary artery. Blood samples were taken from the femoral vein before MI (T0), EA for 30 min (T1), 30 min after MI (T2), 30 min after MI/R (T3) and 120 min after MI/R (T4) for assaying serum tumor necrosis factor (TNF)-alpha and histamine contents by using ELISA. Serum lactate dehydrogenase (LDH) and creatinkinase isoenzyme (CK-MB) levels were measured at T0, T3 and T4 by using an automatic biochemistry analyzer. The infarct size was detected by Evan's blue and tetrazolium chloride (TTC) staining. Myocardial TNF-alpha and histamine contents were detected by ELISA. The percentage of mast cell degranulation was determined by toluidine blue staining.

RESULTS

Following MI/R, serum LDH and CK-MB levels at phase T3 and T4, serum TNF-alpha and histamine contents at phase T2 and T3, and myocardial mast cell degranulation rate increased significantly, and myocardial TNF-alpha and histamine contents decreased in model group in comparison with pre-MI/R (P < 0.05). Compared with IR model group, serum LDH and CK-MB levels at phase T3 and T4, myocardial TNF-alpha and histamine contents all decreased significantly (P < 0.05), but serum TNF-al infarct size was remarkably smaller in EA group than that in IR model group (P < 0.05).

CONCLUSION

"Neiguan" (PC 6)-EA preconditioning has a cardioprotective effect on the ischemia-reperfusion myocardium by promoting mast cell degranulation.