Effects of electroacupuncture on gastric motility and heart rate variability in conscious rats

To clarify the mechanism of site-specific effects of acupuncture on gastric motor function, we studied the simultaneous recording of gastric motility and electrocardiogram (ECG) for heart rate variability (HRV) analysis in conscious rats. Gastric motility and ECG were recorded before, during and after electroacupuncture (EA) at ST-36 (hind limb) or ST-25 (abdomen). EA at ST-36 significantly increased gastric motility and decreased the ratio of low frequency (LF)/high frequency (HF) of the HRV analysis. In contrast, EA at ST-25 significantly inhibited gastric motility and increased LF/HF ratio. There was a significant correlation observed between the changes of gastric motility and LF/HF ratio in response to EA. It is suggested that the stimulatory effect of EA at ST-36 on gastric motility is associated with its stimulatory effect on vagal activity. The inhibitory effect of EA at ST-25 on gastric motility is associated with its stimulatory effect on the sympathetic nerve activity.