Effects and possible mechanisms of acupuncture at ST36 on upper and lower abdominal symptoms induced by rectal distension in healthy volunteers

Abstract

Background acupuncture (AP) has been shown to have a therapeutic potential for gastrointestinal motility disorders. The aims of this study were to investigate the effects and possible mechanisms of acupuncture on postprandial upper and lower abdominal symptoms induced by rectal distension (RD). Twenty healthy volunteers were involved in a two-session study (AP and sham-AP, AP and no-AP, or sham-AP and no-AP). In 12 of the volunteers, RD was performed for 60 min in the postprandial state, and AP at ST36 or sham-AP was performed during the second 30-min period of RD. Gastric slow waves and heart rate variability (HRV) were recorded using the electrogastrogram and electrocardiogram, respectively. Upper and lower abdominal symptoms were scored during RD with AP and sham-AP. In five of the subjects, an additional experiment with two sessions (with AP and no-AP) was performed. In the remaining eight volunteers, the same experiment was performed with sham-AP and no-AP was performed. The results were, first, RD at an average volume of 171 ml induced upper and lower abdominal symptoms (P < 0.01). AP, but not sham-AP or no-AP, reduced both upper and lower abdominal symptoms (P < 0.05). Second, RD decreased the percentage of normal gastric slow waves (P < 0.05). AP improved gastric slow waves compared with sham-AP or no-AP (P < 0.05). Third, in the larger, but not smaller, sample size experiment, the vagal activity during the RD plus AP period was significantly higher than that during the RD alone period in the same session and the corresponding period with sham-AP or no-AP in other sessions (P < 0.05). Neither sham-AP nor no-AP showed any effects on vagal activity (P > 0.05). Finally, in the experiment with eight volunteers, neither sham-AP nor no-AP showed any effects on RD-induced impairment in gastric slow waves, abdominal symptoms, or vagal activity (P > 0.05). The conclusions are RD induces upper or lower abdominal symptoms and impairs gastric slow waves in healthy volunteers. AP at ST36 is able to improve upper and lower abdominal symptoms and impaired gastric slow waves induced by RD, possibly mediated via the vagal pathway.

Ameliorating effects and autonomic mechanisms of needle‐less transcutaneous electrical stimulation atST36 on stress‐induced impairment in gastric slow waves

“…There have been a few studies exploring the correlation between the changes of gastric motility and automatic activity in response to acupuncture/EA at ST36. The vagal mechanism was reported in the effects of acupuncture/EA at ST‐36 on gastric motility and upper abdominal symptoms . In the present study, a substantial increase in HF vagal activity and a decrease in LF sympathetic activity were noted with TEA at ST36, and these effects might have antagonized the effects of the cold stress on the autonomic functions, resulting in normalization of gastric slow waves under the stress.…”

Electroacupuncture via chronically implanted electrodes improves gastric dysmotility mediated by autonomic‐cholinergic mechanisms in a rodent model of functional dyspepsia

“…Previous studies have investigated ameliorating effects of acupuncture or EA on gastrointestinal motility and symptoms . Acupuncture or EA at ST36 has been reported to improve gastrointestinal symptoms such as nausea, vomiting, fullness, satiety and bloating, and to treat digestive diseases . Previous studies from our laboratory revealed EA at ST36 was also able to improve gastric dysrhythmias and antral hypomotility as well as delayed GE, abdominal symptoms induced by RD in dogs .…”

“…A number of studies using the spectral analysis of HRV to explore the autonomic mechanisms of acupuncture/EA at ST36. Most previous studies reported that the effects of acupuncture/EA on gastric dysrhythmias were mediated via the vagal mechanism . In region‐specific effects of acupuncture, Takahashi and co‐workers demonstrated that EA at ST‐36 decreased the ratio of LF/HF in normal rats, suggesting excitatory gastric responses were mediated via the vagal pathway .…”

Effects and mechanisms of auricular electroacupuncture on gastric hypersensitivity in a rodent model of functional dyspepsia

“…A lower vagal tone and higher sympathetic tone were reported in FD patients, compared with healthy persons [21–23]. EA has been consistently shown to regulate autonomic function in clinical and animal studies [27, 40]. Previously AEA on the concha of the ear was shown to increase vagal activity in healthy men [41].…”