Effect of electroacpuncture of Neiguan (PC 6) and Tianquan (PC 2) on skin temperature,blood perfusion,and adrenoceptor response in rats with acute myocardial ischemia

Objective

To investigate the effect of electroacupuncture (EA) of acupoints Neiguan (PC 6) and Tianquan (PC 2) on the skin temperature, blood perfusion, and alpha1- and beta2-adrenoreceptor (α₁-AR and β₂-AR) protein and mRNA level in rats with acute myocardial ischemia.

Methods

Thirty male adult Wistar rats (230 ± 20) g] were randomly assigned into five groups (n = 6 each): a control group, sham operation group, model group, model group treated with EA at low frequency (L-EA, 2 Hz, 1 mA) and model group treated with EA at high frequency (H-EA, 100 Hz, 1 mA). The rat model was prepared by ligating the left anterior descending coronary artery. Electroacupuncture was performed at the left Neiguan (PC 6) for 20min daily for 3 d. After the 3rd time of the treatment, measurements of skin blood perfusion and temperature in Neiguan (PC 6) and Tianquan (PC 2) in all groups were made by laser speckle contrast imaging and infrared thermal image instrument. Real-time PCR and ELISA were used to measure mRNA level and protein level of α_1-AR and β₂-AR in the skin tissues of Neiguan (PC 6) and Tianquan (PC 2), respectively. Serum levels of cTnT and electrocardiogram were used to identify the state of myocardium.

Results

In the group receiving electroacupunture at Neiguan (PC 6), compared with control group, the skin temperature, blood perfusion, and β2-AR mRNA and protein level of model group significantly decreased (P < 0.05), α1-AR mRNA and protein level of model group significantly increased (P < 0.05); compared with model group, the skin temperature, blood perfusion, and β2-AR mRNA and protein level of L-EA significantly increased (P < 0.05), α1-AR mRNA and protein level of L-EA and H-EA significantly decreased (P < 0.05). The same trend has taken place in the former four groups of the Tianquan (PC 2).

Conclusion

Low-or high-frequency electroacupuncture can improve the skin temperature and blood perfusion which may be induced by decreasing the level of α_1-AR and increasing the level of β2-AR of the Neiguan (PC 6) and Tianquan (PC 2) in the rat with acute myocaidial ischemia.