The effect of different frequency electrical acu-stimulation on gastric myoelectrical activity in healthy subjects

Acupuncture has been used to treat gastrointestinal symptoms in oriental countries for many years. The underlying mechanism is still not fully understood.

Fifteen healthy male volunteers were enrolled into this study. A cutaneous electrogastrography recording was obtained. Two frequencies (2 Hz and 100 Hz) of electrical stimulation were applied to Zusnali or Shousanli point in different sessions. Another non-acu-point (2 cm lateral to Zusanli) without electrical stimulation was used for a control study.

There was a significant increase in the percentage of normal frequency during 2 Hz of electrical stimulation on Zusnali (baseline vs. acupuncture, 82.49 +/- 12.87% vs. 93.18 +/- 8.40%, p < 0.01). The percentage of normal frequency did not change significantly, during or after acupuncture, with 100 Hz of electrical stimulation on Zusnali, or 2 Hz and 100 Hz of electrical stimulation on Shousanli. In addition, the percentage of tachygastric frequency and power ratio also changed significantly during 2 Hz of electrical stimulation on Zusnali. However, the change in the percentage of bradygastria and dominant frequency was not statistically significant among all five study sessions during each stage.

The results of this study demonstrated that electrical stimulation, with a frequency of 2 Hz, on Zusanli might enhance the regularity of gastric myoelectrical activity. The effect of acupuncture on gastric myoelectrical activity was acu-point-specific, and that effect was observed with 2 Hz but not 100 Hz electrical stimulation.