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

BACKGROUND/AIMS: Acupuncture has been used to treat gastrointestinal symptoms in oriental countries for many years. The underlying mechanism is still not fully understood. METHODOLOGY: 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. RESULTS: 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. CONCLUSIONS: 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.     

Distension-Induced Myoelectrical Dysrhythmia and Effect of Intestinal Pacing in Dogs

The aims of this study were to investigate the effect of duodenal distension on intestinal myoelectrical activity and to investigate whether intestinal pacing was able to reverse the effects of distension. Six female hound dogs with four pairs of electrodes on the proximal jejunum were involved in this study. The protocol consisted of 30 min of recording of jejunal myoelectrical activity as baseline and 90 min of recording during distension. Intestinal pacing was performed during the second 30 min of distension. Duodenal distension severely impaired intestinal myoelectrical activity. The percentage of normal slow waves was reduced from 90.8 ± 8.4% at baseline to 73.8 ± 10.2%, 57.2 ± 11.4%, and 53.7 ± 16.0% during the first, second and third 30 min of distension (P < 0.05, ANOVA). The dominant power was similarly decreased and the minute-by-minute variation of dominant frequency was significantly increased after distension. Intestinal pacing reversed distension-induced dysrhythmia. The percentage of normal slow waves during the 30 min of distension with pacing was significantly higher than the corresponding 30 min of distension without pacing (88.5 ± 6.6% vs 57.2 ± 11.4%, P < 0.03). It was concluded that intestinal pacing can normalize distension-induced dysrhythmia and has a potential as a future therapeutic modality for intestinal motor disorders.     

Origins and patterns of spontaneous and drug-induced canine gastric myoelectrical dysrhythmia

The aim of this study was to investigate the characteristics and orientation of gastric dysrhythmia using multichannel serosal recordings in dogs. Ten dogs chronically implanted with four to eight pairs of electrodes were studied. Gastric slow waves were recorded in four sessions: postsurgical and after atropine, vasopressin, and glucagon. A total of 554.7 min of bradygastria, 201 min of tachygastria and 22.3 min of arrhythmia were observed in the recordings. The majority of bradygastria (80.5 ± 9.4%) originated in the proximal stomach (P < 0.04, vs other locations) and propagated all the way to the distal antrum. In contrast, tachygastria mainly originated in the distal antrum (80.6 ± 8.8%) (P < 0.04, vs other locations) and propagated partially or all the way to the proximal stomach. Dysrhythmia appeared intermittently with normal gastric slow waves. In all recordings, normal slow waves were present 38.0 ± 5.3% of the time, while bradygastria, tachygastria, and arrhythmia were present 35.9 ± 5.3%, 23.0 ± 1.6%, and 2.4 ± 0.5% of the time, respectively. The prevalence of dysrhythmia was highest in the distal antrum (80.4%) (P < 0.01) and lowest in the proximal part of the stomach. In conclusion, tachygastria originates from an ectopic pacemaker in the distal antrum. It may completely or partially override the normal slow waves. Bradygastria is attributed to a decrease in the frequency of the normal pacemaker in the corpus. The prevalence of gastric dysrhythmia is different in different locations of the stomach and is highest in the distal antrum.     

Impairment of Gastric and Jejunal Myoelectrical Activity During Rectal Distension in Dogs

It is known that distension of the rectum induces gastric hypomotility and delays gastric emptying. Its effect on gastrointestinal myoelectrical activity has not been well studied, however. The aim of this study was to investigate the effects of rectal distension on gastrointestinal myoelectrical activity in dogs. Six hound dogs implanted with electrodes on the serosa of the stomach and proximal jejunum were studied. The protocol consisted of a 30-min baseline recording and another 30-min recording during rectal distension. Gastric myoelectrical activity was severely impaired by rectal distension. The dominant power was significantly decreased from –2.79 ± 0.52 dB at baseline to –4.84 ± 1.26 dB during distension (P < 0.05). The percentage of normal 4–6 cycles per minute gastric slow waves was reduced from 95.08 ± 1.11% to 83.63 ± 4.00% (P < 0.02), and the percentage of tachygastria was increased during distension (0.33 ± 0.19% vs 6.03 ± 1.27%, P < 0.02). The instability coefficient of the dominant frequency was significantly increased (0.134 ± 0.012 vs 0.326 ± 0.074, P < 0.05). The percentage of slow wave coupling was reduced from 93.99 ± 0.76% to 73.43 ± 2.07% (P < 0.00003). In the small bowel, only the instability coefficient of dominant frequency showed a significant increase during distension. Other parameters were not affected by rectal distension. We conclude that rectal distension severely impairs gastric myoelectrical activity. The induced gastric dysrhythmia and reduced slow wave amplitude and coupling may be the underlying pathophysiology of gastric hypomotility and delayed gastric emptying observed during rectal distension.     

Two-Channel Gastric Electrical Stimulation Accelerates Delayed Gastric Emptying Induced by Vasopressin

The aim of this study was to investigate the effects of two-channel gastric electrical stimulation (GES) on delayed gastric emptying, gastric dysrhythmias, and motion sickness-like symptoms induced by vasopressin. Seven dogs implanted with four pairs of gastric electrodes and a duodenal cannula were studied in four randomized sessions (saline, vasopressin, single-channel GES, and two-channel GES). The experiment in each session was conducted sequentially as follows: 30-min baseline, ingestion of a liquid meal, 30-min iv infusion of vasopressin or saline, and two 30-min postprandial recordings. In the GES sessions, GES was applied via the first pair of electrodes for single-channel GES or the first and third pairs of electrodes for two-channel GES. Gastric emptying was collected every 15 min via the cannula for a period of 90 min. Results were as follows. (1) Vasopressin induced gastric dysrhythmias, motion sickness-like symptoms, and delayed gastric emptying (P < 0.01, ANOVA). (2) GES normalized gastric dysrhythmias (P < 0.01) but showed no effects on vasopressin-induced emetic response. (3) Two-channel GES improved delayed gastric emptying induced by vasopressin. In comparison with the vasopressin session, two-channel GES, but not single-channel GES, significantly increased gastric emptying at 30 min (43.9 ± 12.6 vs. 27.5 ± 7.7%; P < 0.03), 60 min (75.3 ± 15.1 vs. 54.0 ± 17.8%; P < 0.05), and 90 min (91.6 ± 9.8 vs. 80.3 ± 9.0%; P < 0.05). GES with long pulses is able to normalize gastric dysrhythmias. Two-channel GES improves delayed gastric emptying induced by vasopressin.     

Cisplatin-Induced Gastric Dysrhythmia and Emesis in Dogs and Possible Role of Gastric Electrical Stimulation

The aim of this study was to investigate the effect of cisplatin on gastric myoelectrical activity and the role of gastric electrical stimulation in the treatment of cisplatin-induced emesis in dogs. Seven dogs implanted with electrodes on the gastric serosa were used in a two-session study. Cisplatin was infused in both the control session and the gastric electrical stimulation session, and gastric electrical stimulation was applied in the gastric electrical stimulation session. Gastric slow waves and emesis, as well as behaviors suggestive of nausea, were recorded during each session. The results were as follows: (1) cisplatin induced vomiting and other symptoms and induced gastric dysrhythmia. The percentage of normal slow waves decreased significantly during the 2.5 h before vomiting (P = 0.01) and the period of vomiting (P < 0.001). (2) Gastric electrical stimulation reduced emesis and the symptoms score. The total score in the control session was higher than that in the gastric electrical stimulation session (P = 0.02). However, gastric electrical stimulation had no effects on gastric dysrhythmia. It is concluded that cisplatin induces emesis and gastric dysrhythmia. Gastric electrical stimulation may play a role in relieving chemotherapy-induced emetic responses and deserves further investigation.     

Effect of electrical stimulation on acupuncture points in diabetic patients with gastric dysrhythmia: a pilot study.

BACKGROUND/AIMS: Abnormal gastric slow-wave frequencies have been observed in diabetic gastroparesis and are associated with impaired antral motor activity. In this study, we aimed at evaluating the effect of acupuncture on gastric slow waves in diabetic patients with symptoms suggesting gastric motor dysfunction. METHODS: Fifteen patients with type II diabetes who had had dyspeptic symptoms for more than 3 months were enrolled. Two acupuncture needles were inserted into the subjects' legs at the Zusanli points, and electrical stimulation (2-Hz pulses) was delivered for 30 min. Cutaneous electrogastrography was performed for 30 min at baseline, for 30 min during acupuncture, and for an additional 30 min after acupuncture. Serum gastrin, motilin, and human pancreatic polypeptide levels were also measured. RESULTS: There was a significant increase in the percentages of normal frequency during and after acupuncture (baseline vs. acupuncture and after acupuncture 21.99 +/- 19.38% vs. 45.93 +/- 19.72 and 48.92 +/- 19.56%; p < 0.01). In addition, the percentage of tachygastric frequency was decreased significantly during and after acupuncture. The dominant frequency was also changed significantly. There was an increase of serum human pancreatic polypeptide during acupuncture (baseline vs. acupuncture 56.96 +/- 27.64 vs. 73.11 +/- 22.37 pmol/l; p < 0.05). CONCLUSIONS: The results of this study revealed that electrical stimulation at the Zusanli points could increase the percentage of normal electrogastrography frequency and decrease the percentage of tachygastric frequency in diabetic patients. The data indicate that acupuncture may enhance the regularity of gastric myoelectrical activity in diabetic patients.     

Effects of Electroacupuncture on Gastric Migrating Myoelectrical Complex in Dogs

The aim of this study was to investigate thecharacteristics of the gastric slow wave duringdifferent phases of the migrating myoelectrical complex(MMC) and the effect of electroacupuncture on the MMC. The experiment was performed in eight hounddogs implanted with one pair of bipolar serosalelectrodes 2 cm proximal to the pylorus. Gastricmyoelectrical activity was recorded for three completecycles of the MMC in two sessions, one withelectroacupuncture at points ST36 and PC6 and the otherat sham points. The acupuncture was performed for 30 minin phase I of the second cycle of the MMC. Spectral analysis was performed to compute the frequencyand power (amplitude) of the gastric slow wave, whereasblind visual analysis was applied to compute theappearance of spike potentials and the length of each phase of the MMC. It was found that therewas a significant difference in the frequency and powerof the gastric slow wave during different phases of theMMC (P < 0.05). Phase I was characterized with the highest frequency and lowest power ofthe gastric slow wave, whereas phase III exhibited thehighest power in the slow wave. It was also found thatin comparison with the sham points, electroacupuncture at the acupoints increased the number of spikebursts. This increase was not significant during the MMCcycle with electroacupuncture (34.4 ± 4.1 vs 27.5± 2.5%, P > 0.05) but became significant during the cycle after electroacupuncture (39.8± 3.3% vs 27.5 ± 2.5%, P < 0.0005).Similarly, during the MMC cycle after electroacupunctureat the acupoints, there was a significant decrease in the length of phase I (14.8 ± 2.2 vs46.9 ± 6.1 min, P < 0.003) and a significantincrease in the length of phase II (75.6 ± 9.9 vs30.6 ± 4.1 min, P < 0.003) and phase III (25.8± 0.6 vs 22.1 ± 0.7 min, P < 0.003). A similarincrease was observed during the MMC cycle withelectroacupuncture but was not statisticallysignificant. In conclusion, the gastric slow wave hasthe highest power during phase III of the MMC, indicatingthat the antral contraction is characterized not only bythe appearance of spikes, but also by the increasedpower of the slow wave. Electroacupuncture at acupoints of ST36 and PC6 enhances the gastric MMC byreducing the length of phase I and increasing the lengthof phases II and III.     

Nizatidine accelerates gastric emptying of a solid meal in rats

Nizatidine, a new histamine-2-receptor antagonist, stimulates gastrointestinal motility in dogs and gastric emptying of liquids in rats. Effect of nizatidine on gastric emptying of a solid meal was investigated using a novel gastric emptying model in rats. Male Wistar rats (weighing 200–300 g) were supplied with powdered food containing 30 w/w% barium 14 hr before the beginning of the experiment and x-ray photography of rat stomach was taken under light ether anesthesia. Gastric emptying was assessed by percentage of a decrease in area 30 min after drug was injected intraperitoneally. There was a positive correlation between the area of the gastric outline and the weight of the gastric contents (r=0.94,P<0.01). Ether anesthesia itself did not affect gastric emptying. Nizatidine increased gastric emptying dose-dependently (emptied percentage; vehicle: 4.9±1.5%, 1 mg/kg: 7.2±0.4%, 3 mg/kg: 10.4±2.0%, 10 mg/kg: 16.7±4.9%, 30 mg/kg: 25.7±7.4%).N-Desmethyl nizatidine (NDM) also stimulated gastric emptying, but nizatidineS-oxide, cimetidine, an famotidine had no significant effects on gastric emptying. Nizatidine and neostigmine, but not NDM, at a subthreshold dose accelerated gastric emptying treated with a low dose of acetylcholine (0.1 mg/kg). Atropine (2 mg/kg, –30 min) did not modulate the gastroprokinetic action of nizatidine, but blocked that of NDM. These findings suggest that this noninvasive method may allow measurement of gastric emptying of solids accurately and that nizatidine and NDM facilitate gastric emptying probably mediated by a direct and/or an indirect (acetylcholinesterase inhibition) cholinergic mechanism.     

Inhibitory reflexive effect of rectal distension on postprandial gastric myoelectrical activity

The aim of the study was to determine the effects of low-volume rectal distension on gastric myoelectrical activity. The study was performed in 14 healthy volunteers in 2 randomized sessions. In the control session, a small balloon was inserted into the rectum 10 cm beyond the anal verge and inflated with 20 ml of air. Gastric myoelectrical activity was recorded for 30 minutes in the fasting state and 30 minutes after a meal; and then the balloon was deflated and removed, and another 30-min recording was followed. The study session was the same except that after the 30-min baseline recording the balloon was inflated to reach a volume with which the subject felt an urgency for defecation. Spectral analyses were performed to compute the dominant frequency, power, and regularity (2–4 cycles/minutes, cpm) of the gastric slow waves and the percentage of gastric dysrhythmia. Results: 1). In comparison with our previously published data, the placement of the rectal balloon with a volume of 20 ml air did not affect the regularity of the slow waves (84.2 ± 3.6% in fasting, 85.3 ± 4.3% in fed); In comparison with the control session, the rectal distension inducing an urgency for defecation (average volume of air: 72.5 ml) significantly reduced the regularity of gastric slow waves in the fed state (72.0 ± 5.7%, P < 0.03 vs baseline; P < 0.02, vs control session) but not in the fasting state (80.1 ± 4.5%, P = 0.1). This postprandial change was attributed to a significant increase in bradygastria (3.1 ± 1.0% vs 7.9 ± 2.6%, P < 0.04) and a marginal increase in tachygastria (7.4 ± 2.5% vs 15.8 ± 4.3%, P = 0.06). The normal postprandial increases in the dominant frequency and power of the gastric slow wave were abolished in both sessions. conclusions, rectal distension evoking an urgency for defecation impairs postprandial gastric slow waves with an increase in the percentage of both bradygastria and tachygastria.     

Postprandial Response of Jejunal Slow Waves and Mediation via Cholinergic Mechanism

The postprandial characteristics of jejunalmyoelectrical activity and its mediation via cholinergicnerves were investigated in this study. Four pairs ofbipolar electrodes were implanted on the serosa of the proximal jejunum of nine female hounddogs (14-22 kg). In the control session, the recordingof jejunal myoelectrical activity was made for 30 min inthe fasting state and for 90 min after a solid meal (0.45 kg, 838 kcal). The study sessionfollowed the same protocol except that a bolus of 0.25mg/kg atropine was injected intravenously 30 min afterthe meal. Computerized spectral analysis was performed to calculate the frequency, power, andpercentage of 17-22 cycles/min (cpm) slow waves. Aspecial artificial neural network program was applied tocompute the spike bursts superimposed on slow waves. All data were expressed as mean ± SE. Thepostprandial frequency of the jejunal slow waves wassignificantly increased from 18.42 ± 0.28 cpm inthe fasting state to 18.95 ± 0.22, 19.28 ±0.23, and 19.28 ± 0.22 cpm during the first, second, andthird 30-min periods after the meal (all P < 0.03 incomparison with the fasting state). The percentage ofthe slow waves superimposed with spike bursts was increased from 19.33 ± 3.90% at fastingstate to 35.16 ± 2.76%, 32.87 ± 4.06%, and34.88 ± 3.51% during the first, second, and third30-min periods after the meal (all P < 0.03 incomparison with fasting state). Atropine abolished thepostprandial increases in the frequency of slow wavesand the number of spike bursts. No significantpostprandial changes in the power and the percentage of17-22 cpm slow waves were observed. In conclusion,the postprandial response of the jejunal slow wavesafter a solid meal presents as an increase of thefrequency of slow waves and the number of the spikebursts which can be abolished by atropine, and thepostprandial response of the jejunal slow waves is aneural reflex dominantly mediated via vagal cholinergicnerves.     

Inhibitory effect of white wine on gastric myoelectrical activity and the role of vagal tone

Although extensively investigated throughout the gastrointestinal tract, the influence of alcohol on gastric motility is still unclear. Our aim was to investigate the effect of wine on gastric myoelectrical activity and vagal activity. Ten healthy subjects were studied in two sessions with the electrogastrogram (EGG) for 30 min at baseline, 30 min after ingesting the test liquid [white wine (12.5% alcohol) or matched juice], and 60 min after a standard test meal. Spectral analysis was performed to compute EGG parameters and their postprandial changes. The vagal activity was assessed based on spectral analysis of the heart rate variability (HRV) signal derived from the ECG recording. White wine preload significantly diminished the postprandial increase in EGG dominant power compared to juice preload (1.16 ± 1.57 vs 5.48 ± 1.01 dB, P < 0.001). A significant decrease in vagal activity was observed after wine (23.40 ± 4.30 vs 17.43 ± 3.40%, P < 0.005), which remained unchanged after the test meal (23.40 ± 4.30 vs 16.77 ± 4.40%, P < 0.05). This decrease was not noted in the juice session. A correlation was established between changes after wine consumption in EGG dominant power and in the percentage of the vagal activity (r = 0.89, P < 0.05). In conclusion, white wine preload inhibits the postprandial EGG dominant power, suggesting a possible inhibition of postprandial gastric contractions. This effect may be associated with diminished vagal activity.     

Electroacupuncture Elicits Dual Effects: Stimulation of Delayed Gastric Emptying and Inhibition of Accelerated Colonic Transit Induced by Restraint Stress in Rats

Acupuncture has been used for treating functional gastrointestinal (GI) disorders. Animal studies have demonstrated that acupuncture antagonized various stress-induced responses. We investigated the effects of electroacupuncture (EA) at ST-36 (Zusanli; lower limb) on stress-induced alteration of GI motor activities. Solid gastric emptying was significantly delayed by restraint stress (29.6±2.4%; n=7) compared to that of controls (60.0±2.5%; n=8). Delayed gastric emptying was significantly improved by EA at ST-36 (47.2±1.8%). Intracisternal (IC) injection of corticotropin releasing factor (CRF; 1 μg) delayed gastric emptying to 25.4±3.1%, which was also improved by EA at ST-36, to 53.0±7.1% (n=8). The stimulatory effect of EA on stress-induced delayed gastric emptying was abolished by atropine (17.6±1.9%) but not by guanethidine (42.2±2.3%). Colonic transit was significantly accelerated by restraint stress (GC=7.2±0.3; n=8) compared to that of controls (GC=5.2±0.2; n=8). Accelerated colonic transit was significantly reduced by EA at ST-36 (GC=4.9±0.3). IC injection of CRF accelerated colonic transit (GC=6.9±0.2), which was also normalized by EA at ST-36 (GC=4.7±0.2). The inhibitory effect of EA on stress-induced acceleration of colonic transit was not affected by guanethidine (GC=4.6±0.3). In conclusion, EA at ST-36 showed dual effects: stimulation of stress-induced delayed gastric emptying and inhibition of stress-induced acceleration of colonic transit. The stimulatory effect of EA on stress-induced delayed gastric emptying is mediated via cholinergic pathways. The inhibitory effect of EA on stress-induced acceleration of colonic transit is independent of the sympathetic pathway.     

Vomiting and gastric electrical dysrhythmia in dogs

Background: The correlation between gastric myoelectrical activity (GMA) and gastrointestinal symptoms such as nausea and vomiting is poorly understood. The aim of this study was to assess the association of GMA with vomiting induced by retrograde gastric electrical stimulation or duodenal balloon distention. Methods: Ten dogs were involved in this study. Vomiting was induced by retrograde gastric electrical stimulation in 6 dogs and by duodenal balloon distention in 4 dogs. Computerized spectral analysis and visual analysis were applied to detect the GMA change during various periods before and after vomiting. Results: Gastric dysrhythmia preceded vomiting but was of brief duration. The major pattern of dysrhythmia immediately before vomiting was tachyarrhythmia and gastric slow wave was completely uncoupled before vomiting. Gastric dysrhythmia and slow wave uncoupling were also noticed immediately after vomiting but the dogs recovered quickly. The major pattern of dysrhythmia after vomiting was arrhythmia. GMA was normal during the periods other than 5?min before and during vomiting and 5?min after vomiting. Conclusions: Gastric dysrhythmia seems to be the cause of vomiting induced by retrograde gastric electrical stimulation or duodenal balloon distention. It is brief and characterized with tachyarrhythmia and uncoupling.     

Acupuncture inhibits vagal gastric acid secretion stimulated by sham feeding in healthy subjects.

In a prospective randomised study, the effect of acupuncture on sham feeding stimulated gastric acid secretion was investigated. In eight healthy volunteers (five men, three women, mean (SEM) age 26.3 (4.7) years) various methods of acupuncture were performed. Apart from the sham procedure, the acupuncture was performed at the classic acupuncture points. Electroacupuncture reduced gastric acid secretion expressed as median (range) significantly during the first 30 minute period to 1.6 (0-5.2) mmol compared with 3.8 (2.3-14.5) mmol (p < 0.05) during control period (sham feeding without acupuncture). Inhibition of gastric acid secretion by electroacupuncture was also significant during the second 30 minute period (0.2 (0-5.6) v 3.6 (0.3-9.1) mmol; p < 0.05) and for peak acid output (0.8 (0.2-5.1) v 7.6 (3.4-12.1) mmol; p < 0.05). Transcutaneous electrical nerve stimulation also resulted in significant reduction of gastric acid secretion during the first 30 minute period (1.0 (0-3.6) mmol v 3.8 (2.3-14.5) mmol; p < 0.05), and peak acid output (3.6 (1.2-12.0) v 7.6 (3.4-12.1) mmol; p < 0.05). The classic needle acupuncture, laser acupuncture, and sham acupuncture had no significant effect on gastric acid secretion. This study shows firstly that in healthy volunteers, only the versions of acupuncture using more pronounced stimulation (electroacupuncture, transcutaneous electrical nerve stimulation), but not those with only mild stimulation of the nerves (classic needle acupuncture, laser acupuncture), and secondly only acupuncture performed at defined points lead to significant reduction in gastric acid secretion.     

Cisapride in treatment of roux-en-Y syndrome

After Roux-en-Y gastrojejunostomy patients frequently complain of upper abdominal pain, fullness, nausea, and vomiting. This Roux-en-Y syndrome is caused by slow gastric emptying, Roux-limb stasis, or both. Treatment of this syndrome is cumbersome. We evaluated the effect of cisapride on complaints and on transit through gastric remnant and Roux limb in 24 such patients. Thirteen of them had slow gastric emptying and 13 had stasis in the Roux limb (two patients had both). Symptoms and transit were evaluated before and after three weeks of treatment using a questionnaire and scintigraphy. Responding subjects continued therapy and were interviewed again after six months. Seven patients with slow gastric emptying and three patients with Roux-limb stasis had enduring symptomatic relief; all exhibited accelerated transit during therapy: mean half gastric emptying time in the seven patients with slow gastric emptying was 204±89 min before and 111±59 min during cisapride (P<0.05); mean percentage of radioactivity, emptied from the gastric remnant, which remained in the Roux limb at 60 min in the three patients with Roux limb stasis was 74±4% before and 25±10% during cisapride (P<0.05). In patients without symptomatic response, transit did not improve. Conclusion: with cisapride long-lasting symptomatic relief and improved transit is achieved in about 40% of patients with the Roux-en-Y syndrome.This work was supported by the Jan Kornelis de Cock-Stichting. Cisapride was provided by Janssen Pharmaceutica B.V., Tilburg, The Netherlands.     

Hyperglycemia Attenuates Erythromycin-Induced Acceleration of Liquid-Phase Gastric Emptying of Hypertonic Liquids in Healthy Subjects

Acute hyperglycemia has been associated with delayed gastric emptying in healthy controls. Erythromycin has recently been found to be a gastrointestinal prokinetic agent in both solids and hypertonic liquids. Our aim was to examine whether the acute steady-state hyperglycemia reduces the erythromycin-induced acceleration of gastric emptying of hypertonic liquids after a fasted state of the stomach in healthy subjects. In 12 healthy subjects scintigraphic measurement of gastric emptying of a hypertonic radiolabeled liquid meal, during normoglycemia (5–8.9 mmol/l glucose) or induced hyperglycemia (16–19 mmol/liter glucose) by intravenous glucose infusion after giving either placebo or 200 mg intravenous erythromycin, was performed on four separate days in random order. In the hyperglycemic state compared with normoglycemia, either after placebo administration or erythromycin, the gastric emptying of the hypertonic liquid was reduced. The lag-phase duration was significantly increased (17.5 ± 5.5 min, and 7.2 ± 4.5 min vs 10.5 ± 3.4 min, and 3.5 ± 2.5 min, respectively, P < 0.0001) as were the overall T1/2 (gastric emptying time of the half meal) (52.5 ± 13 min and 24.5 ± 5.5 min vs 42 ± 10.5 min, and 16 ± 6 min, respectively, P < 0.0001) and the percentage of liquid meal retained in the stomach at 60 and 100 min postprandially (P < 0.001). In conclusion, hyperglycaemia attenuates the acceleration effect of erythromycin and decreases the overall gastric emptying rate of hypertonic liquids in healthy subjects.     

Cutaneous electrical stimulation of acupuncture points may enhance gastric myoelectrical regularity

BACKGROUND/AIM: Cutaneous electrical stimulation has been reported to be as effective as electroacupuncture. The aim of this study was to test whether cutaneous electrical stimulation had the same effect as electroacupuncture to enhance the regularity of myoelectrical activity. METHODS: Fifteen healthy male volunteers were enrolled for this study. Electrogastrography (EGG) was performed for 30 min at the baseline, 30 min during electroacupuncture or cutaneous electrical stimulation, and for an additional 30 min thereafter. RESULTS: During 3 Hz of electroacupuncture on the Zusanli point, there was a significant increase in the percentage of normal frequency. The percentage of normal frequency in the post-acupuncture period was also increased, but it was not statistically significant when compared to the baseline. There was a significant decrease in the tachygastric and bradygastric rhythm during electroacupuncture on the Zusanli points. There were similar changes of EGG parameters with cutaneous electrical stimulation on the Zusanli points. The percentage of normal frequency during cutaneous electrical stimulation increased significantly. However, the percentage of normal frequency in the post-cutaneous electrical stimulation period was similar to the baseline. There was a significant decrease in the percentage of tachygastric rhythm during cutaneous electrical stimulation on the Zusanli points. However, there was no significant change in the percentage of bradygastric rhythm during and after the cutaneous electrical stimulation periods. CONCLUSIONS: The effect of cutaneous electrical stimulation on the percentage of normal frequency and tachygastria is similar to electroacupuncture. Nonetheless, the changes of the percentage in bradygastria are not significant.     

Alteration of gastric myoelectrical and autonomic activities with audio stimulation in healthy humans

Cold or emotional stress was reported to affect gastric myoelectrical activity. The aim of this study was to investigate the effects of music or noise on gastric myoelectrical activity and autonomic function in healthy volunteers.

Material and methods

The study was performed in 10 fasted healthy volunteers and included 30 min at baseline, 30 min of classical music via headphones and 30 min of loud household noises via headphones. The electrogastrogram (EGG) readings were recorded simultaneously with the electrocardiogram (ECG) recording.

Results

Both classical music and noise altered the regularity of gastric slow waves. The percentage of normal 2–4 cycles/min (cpm) waves was reduced from 77.9±4.7% at baseline to 66.9±5.4% during music (p<0.006) and 67.7±5.4% during noise (p<0.05). The reduction was attributed to a significant increase in bradygastria (15.8±3.9% versus 9.8±2.6%, p<0.04) with the music and a significant increase in arrhythmia (7.4±1.6% versus 2.0±1.1%, p<0.02) with the noise. The dominant frequency and power of the EGG were, however, not altered with either music or noise. Neither music nor noise had any effect on the autonomic function assessed by the heart rate variability.

Conclusions

Audio stimulation, with both music and noise, alters the rhythmicity of gastric slow waves. Classical music seems to increase bradygastria, whereas, household noise may increase arrhythmia. The effect of audio stimulation on the gastric slow wave does not seem to involve sympathetic or vagal efferent pathways assessed by the spectral analysis of heart rate variability.     

Effects of Gastric Electrical Stimulation with Short Pulses and Long Pulses on Gastric Dysrhythmia and Signs Induced by Vasopressin in Dogs

Aims: This study was to investigate the effect of gastric electrical stimulation (GES) with short pulses, long pulses, short-pulse trains or long-pulse trains on gastric dysrhythmia and motion-sickness signs induced by vasopressin. Methods: Seven male beagle dogs implanted with four pairs of electrodes on gastric serosa were studied. The study was performed in six sessions in a randomized order. In session 1 or 2, either saline or vasopressin was infused without GES. In session 3, 4, 5 and 6, GES with short pulses, long pulses, trains of short pulses or trains of long pulses was performed before and during vasopressin infusion. Gastric slow waves and motion-sickness signs were recorded in each session. Results: (1) Vasopressin induced gastric dysrhythmia and motion sickness-like signs (ANOVA, P < 0.001). (2) GES with short pulses or trains of short pulses was capable of preventing vasopressin-induced emetic response (P < 0.001), but did not normalize gastric dysrhythmia. (3) GES with long pulses or trains of long pulses was able to normalize gastric dysrhythmia induced by vasopressin (P < 0.001), but showed no effects on vasopressin-induced motion-sickness signs. Conclusion: GES with short pulses or trains of short pulses prevents vasopressin-induced emetic response with no improvement in gastric dysrhythmia. GES with long pulses or trains of long pulses normalizes gastric dysrhythmia induced by vasopressin with no effects on signs. Xiaohua Hou and Geng-Qing Song contributed equally to this work.