Objective: To observe the effect of low-frequency or high-frequency electroacupuncture (EA) stimulation of "Neiguan" (PC 6) on changes of skin blood perfusion volume of heart-related and heart-irrelevant acupoints in rats with normal or ischemic myocardium.
Methods: Wistar rats were randomly divided into the control, sham-operation, model, low-frequency EA and high-frequency EA groups (n=8 in each group). The myocardial ischemic (MI) model was established by occlusion of the anterior descending branch of the left coronary artery. 2 Hz and 100 Hz EA was respectively applied to left PC 6 for 20 min, once daily, a total of three times. Electrocardiogram (ECG) was recorded after the last treatment. Serum cardiac troponin T (cTnT) contents were assayed by ELISA. The skin blood perfusion volumes of bilateral PC 6, "Zusanli" (ST 36) and "Yanglingquan" (GB 34) were observed by laser speckle contrast imaging.
Results: In comparison with the control and sham-operation groups, the differences of "J point" and contents of serum cTnT were significantly increased in the model group (P<0.01). After EA, the differences of "J point" and contents of serum cTnT were significantly decreased in both low-frequency and high-frequency EA groups (P<0.01, P<0.05). Compared with the control group, the skin blood perfusion volumes of bilateral PC 6 and ST 36 decreased obviously in rats of the model group (P<0.01). After EA, the skin blood perfusion volumes were markedly up-regulated in the areas of PC 6 and ST 36 (P<0.01). There were no significant changes in that of GB 34 among the 5 groups (P<0.05).
Conclusions: Skin blood perfusion volumes around PC 6 and ST 36 can specifically reflect the change of the myocardial state.