J. D. Z. Chen

Transcutaneous electroacupuncture improves dyspeptic symptoms and increases high frequency heart rate variability in patients with functional dyspepsia

Abstract  The aim of the study was to evaluate the therapeutic value and possible mechanisms of transcutaneous electroacupuncture (TEA) in a double‐blind and cross‐over study in patients with functional dyspepsia (FD). Twenty‐seven patients with FD were enrolled and the study consisted of two parts: (i) acute effects of TEA at PC6 and ST36 on gastric slow waves and heart rate variability and (ii) chronic (2 weeks) effects of TEA at PC6 and ST36 on dyspepsia symptoms, gastric slow waves, heart rate variability and neuropeptide Y (NPY) and motilin. The results of this study are: (i) The dyspepsia symptom score was decreased by 55% at the end of chronic TEA and the improvement was significant (P < 0.01); (ii) the high frequency (HF) assessed from the spectral analysis of heart rate variability was markedly increased with both acute TEA (76% increase, P = 0.01) and chronic TEA (75% increase, P = 0.025); (iii) gastric slow waves were not altered by either acute or chronic TEA; and (iv) the plasma level of NPY but not motilin was increased after chronic TEA. Non‐invasive and needleless transcutaenous electroacupuncture at ST36 and PC6 markedly improves dyspepsia symptoms and the improvement may be associated with the increase in HF heart rate variability and the modulation of NPY.

Transcutaneous Electrical Nerve Stimulation (TENS) Improves Upper GI Symptoms and Balances the Sympathovagal Activity in Scleroderma Patients

To assess the impact of transcutaneous electrical nerve stimulation (TENS) at gastrointestinal (GI) acupoints on GI symptoms and quality of life in scleroderma patients, 17 patients filled out SF-36 and GI symptom questionnaires before the electrocardiogram was recorded for two intervals: baseline and TENS. At home, patients applied TENS for 14 days, then were reassessed.Acutely, TENS application significantly increased sympathetic and vagal activities vs. baseline (P= 0.02 and P= 0.004), respectively. Prolonged TENS application normalized the sympathovagal balance (P= 0.04), decreased GI symptom scores (P= 0.02) and increased the physical functioning score (SF36), which strongly correlated with the change in the sympathovagal balance (r= 0.6, P= 0.02). In conclusion, TENS at GI acupoints offers a potential option in the treatment of upper GI symptoms, but further study is necessary.

Hepatic electrical stimulation reduces blood glucose in diabetic rats

Background  The aim of this study was to investigate the feasibility and mechanisms of controlling blood glucose using hepatic electrical stimulation (HES).

Neural mechanisms involved in the inhibition of intestinal motility induced by intestinal electrical stimulation in conscious dogs.

Abstract  The effects and mechanisms of intestinal electrical stimulation (IES) with long pulses on intestinal motility were investigated in conscious dogs. Eighteen dogs were equipped with serosal electrodes and an intestinal cannula in the small bowel. The first experiment was designed to study the effect of one‐channel IES on intestinal motility and the extent of this effect. The second experiment was conducted to study the effect of IES on intestinal motility and the involvement of neural pathway. The IES with long pulses significantly inhibited intestinal motility. Intestinal motility of the entire measured segment (40–220 cm distal to the stimulation electrodes) was inhibited by 60–74% with the single‐channel IES with long pulses. Hexamethonium, guanethidine, phentolamine, propranolol partially, but not N‐nitro‐l‐arginine (l‐NNA), ondansetron and naloxone prevented the inhibitory effect of IES on intestinal motility. We conclude that single‐channel IES inhibits intestinal motility within a distance of at least 2 m. This inhibitory effect induced by IES with long pulses is mediated via sympathetic but not nitrergic, serotoninergic 5‐HT3 and opiate pathway.

Efficacy and efficiency of gastric electrical stimulation with short pulses in the treatment of vasopressin‐induced emetic responses in dogs

Abstract  The aim of this study was to determine the most effective and efficient anti‐emetic parameters of short‐pulse gastric electrical stimulation (GES) in dogs. Seven female beagle dogs implanted with four pairs of gastric electrodes were studied in eight randomized sessions (saline, vasopressin, and six GES sessions with different parameters). Each session consisted of four 20‐min recordings of gastric slow waves and symptoms. In sessions 1 and 2, saline and vasopressin, respectively, were infused during the second 20‐min period. The protocol of the other six sessions was the same as session 2 except that GES was continuously applied. It was found that: (1) vasopressin induced gastric dysrhythmia and emetic response (P < 0.01, anova); (2) short‐pulse GES with a frequency of 14 or 40 Hz and pulse width of 0.1 or 0.3 ms, but not 0.6 ms was able to reduce symptoms induced by vasopressin; (3) short‐pulse GES with a pulse width of 0.3 ms was the most effective in preventing vasopressin‐induced symptoms; (4) none of the tested GES methods improved vasopressin‐induced gastric dysrhythmia. We conclude that vasopressin induces gastric dysrhythmia and symptoms. Short‐pulse GES with a pulse width of 0.3 ms and frequency of 14 Hz is most effective and efficient in preventing vasopressin‐induced emetic responses in dogs.

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

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.

Electroacupuncture improves burn-induced impairment in gastric motility mediated via the vagal mechanism in rats

Delayed gastric emptying (GE) is common in patients with severe burns. This study was designed to investigate effects and mechanisms of electroacupuncture (EA) on gastric motility in rats with burns.

Intestinal electrical stimulation improves delayed gastric emptying and vomiting induced by duodenal distension in dogs

Abstract  The aim of this study was to investigate the effects of short‐pulse intestinal electrical stimulation (IES) on duodenal distention‐induced delayed gastric emptying and vomiting in dogs and its possible mechanisms. The study was performed in 12 dogs with jejunal electrodes and a duodenal cannula in three separate experiments to investigate the effects of IES on duodenal distension (DD)‐induced delayed gastric emptying and discomfort signs, vagal efferent activity, and jejunal tone. We found that: (i) IES significantly accelerated gastric emptying of liquid delayed by distension (18.05 ± 4.06%vs. 7.18 ± 1.99%, P = 0.036 at 60 min). (ii) IES significantly reduced vomiting and discomfort/pain induced by distension. The average signs score was 15.33 ± 1.37 during distension which decreased to 6.50 ± 0.91 (P = 0.0002) with IES. (iii) IES did not change vagal afferent activity, which was assessed by the spectral analysis of the heart rate variability. (iv) IES decreased jejunal tone. In conclusion, IES with parameters commonly used in gastric electrical stimulation for nausea and vomiting associated with gastroparesis improves DD‐induced delayed gastric emptying and prevents DD‐induced vomiting and discomfort signs. Further studies are warranted to investigate the therapeutic potential of IES for gastrointestinal symptoms associated with disturbances in motility and sensory function in small intestine.

Effects and mechanisms of electroacupuncture on glucagon-induced small intestinal hypomotility in dogs

Background  Little is known on the effect of electroacupuncture (EA) (Br Med J, 2, 1976, 1225) on intestinal motility. The aim of this study was to investigate effects and mechanisms of EA on small intestinal contractions, transit, and slow waves in dogs.

Development of gastric slow waves and effects of feeding in pre‐term and full‐term infants

Abstract  The aims of this study were to investigate the difference in developmental process of gastric slow waves and the effects of feeding in pre‐term and full‐term infants. Twenty‐six pre‐term and 31 full‐term infants were enrolled in the study. Gastric myoelectrical activity was recorded using electrogastrography (EGG) from birth to month 6. (1) An increase in the % of 2–4 cpm slow waves was noted in both pre‐term (P < 0.01) and full‐term infants (P < 0.04) from birth to month 4. (2) The pre‐term infants showed a reduced dominant EGG power at certain points of the study. (3) Breast or formula feeding resulted in no difference in the EGG in the full‐term infants and showed a difference in the postprandial dominant power of the EGG in the pre‐term infants only at month 2 after birth (P < 0.05) but not at other times. The gastric slow wave in pre‐term infants is of a significantly reduced amplitude but similar rhythmicity. The method of feeding has no effects on the EGG in full‐term infants and minimal effects (may be of non‐clinical significance) on the EGG in pre‐term infants as the difference was noted only at one time point during the 6‐month follow‐up study.