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

OBJECTIVE: 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. MATERIALS 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.     

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.     

Enhanced postprandial gastric myoelectrical activity after moderate-intensity exercise

OBJECTIVE: The aim of this study was to investigate the change of postprandial gastric myoelectrical activity and its relation with vagal activity after exercise. METHODS: Nine subjects were studied in two sessions. In the control session, gastric myoelectrical activity was recorded using electrogastrography (EGG) for 30 min in the fasting state and 60 min after a test meal. In the exercise session, after the baseline recording of both the EGG and electrocardiogram (ECG), the subject was put on a cycle ergometer for exercise until reaching 50% of the maximum age-predicted heart rate for 10 min. The test meal was then given and the recording was resumed for 60 more minutes. Spectral analyses were performed on both the EGG and the heart rate variability derived from the ECG. RESULTS: The postprandial increment of the dominant power (p<0.05) and the percentage of the 2-4 cpm slow waves (p = 0.01) were significantly higher with exercise. The standard deviation of the postprandial dominant frequency was significantly decreased (more stable slow waves) with exercise (p<0.04). While cardiac vagal activity was significantly decreased after the meal, exercise did not significantly affect the postprandial change. CONCLUSIONS: Gastric slow waves become more regular, more stable, and of higher amplitude after exercise, and this enhancement is probably not mediated via the vagal pathway.     

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.     

Clonidine Inhibits Postprandial Response of Antral Myoelectrical Activity

Clonidine, an ₂-adrenergic agonist, is known to inhibit gastric motility and delay gastric emptying in both humans and animals, but its effect on gastric myoelectric activity is unclear. The aim of this study was to investigate the effect of clonidine on postprandial gastric myoelectric activity. The experiment was performed in eight hound dogs (14.5–22.6 kg) implanted with three pairs of bipolar serosal electrodes with an interval of 4 cm and the most distal pair 2 cm above the pylorus. Each dog was studied twice on two separate days after a complete recovery from surgery. Gastric myoelectrical activity was recorded for 30 min in the fasting state and 90 min after a solid test meal of 838 kcal. Two tablets of clonidine (0.4 mg) were given with the meal in one of the sessions. The dominant frequency and power of the slow waves from the most distal pair were calculated by computerized spectral analysis. All data were expressed as mean ± se. A significant postprandial increase in the dominant power of the slow wave and an increase in the percentages of gastric slow waves with spike bursts were observed in the control session, whereas the dominant frequency of gastric slow waves showed a significant postprandial decrease after the meal. The dominant power increased 8.24 ± 0.5, 8.6 ± 0.2, and 7.5 ± 0.3 dB, respectively, in the first, and second, and third 30-min period after the meal (all P < 0.01 vs baseline). Clonidine completely abolished the postprandial increase in the dominant power of the gastric slow wave and significantly inhibited spike bursts. The dominant power only increased 2.4 ± 1.1 dB (P > 0.05 vs baseline; P < 0.01 vs the first postprandial period in the control session), 0.6 ± 1.5 dB (P > 0.05 vs baseline; P < 0.05 vs the second postprandial period in the control session) and –1.5 ± 2.2 dB (P > 0.05 vs baseline; P < 0.05 vs the third postprandial period in the control session) respectively during the first, second, and third periods after the meal and clonidine. However, it did not affect the postprandial change of the dominant frequency of gastric slow waves. No significant changes in percentage of regular slow waves were noted with the meal or with clonidine (P > 0.05). In conclusion, the postprandial response of gastric myoelectrical activity in dogs to a solid meal is featured with an increase in amplitude and spike bursts, which is inhibited by clonidine.     

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.     

Gastric myoelectrical activity and gastric emptying in patients with functional dyspepsia

OBJECTIVES: The aims of this study were to investigate gastric myoelectrical activity and gastric emptying (GE) and their relationship in patients with functional dyspepsia. METHODS: The study was conducted in 15 healthy volunteers (six women, nine men, mean age: 42 yr) and 15 patients (13 women, two men, mean age: 43 yr) with functional dyspepsia. Gastric myoelectrical activity was recorded using cutaneous electrogastrography (EGG) for 30 min in the fasting state and for 120 min simultaneously with GE monitoring after an isotope-labeled solid meal. The anterior/posterior images of the stomach were taken using a technetium scanner immediately after eating, and then at 1, 2, and 4 h to determine the percentage of gastric retention. The dominant frequency of the EGG, the change of the postprandial EGG peak power (deltaP), and the percentage of normal 2-4 cycles/min (cpm) slow waves during each recording session were calculated and compared between the patients and healthy subjects. RESULTS: The patients had a significantly lower mean percentage of 2-4 cpm slow waves, both in the fed state and in the fasting state, than did healthy subjects. Compared to the EGG in the fasting state, a significant increase of the EGG dominant frequency in the fed state was observed in healthy subjects but not in the patients. The mean postprandial EGG power increase in the patients was substantially less than in the healthy subjects during the first postprandial hour but similar during the second postprandial hour. The mean percentage of gastric retention in patients is substantially higher than in the healthy subjects, both at 2 h after eating and at 4 h after eating. Of 15 patients, nine (60%) had delayed GE (gastric retention at 2 h >50%) and 10 (66%) had abnormal EGGs (percentage of 2-4 cpm <70% and/or deltaP < 0). Eight of these 10 patients (80%) with abnormal EGGs had delayed GE. CONCLUSIONS: A high proportion of adult patients (60%) with functional dyspepsia have abnormally slow GE and abnormalities in gastric myoelectrical activity.     

Pathophysiological roles of ectopic tachygastria induced with antral electrical stimulation

AIM: To investigate the pathophysiological roles of tachygastria using antral electrical stimulation (AES). METHODS: The study was performed on 13 healthy female hound-type dogs chronically implanted with three pairs of serosal electrodes and a gastric cannula (n = 7). In the first experiment (n = 7), the antral motility was measured for three 30-min periods right after a solid meal. AES was performed during the second 30-min period at a tachygastric frequency. In the second experiment (n = 6), gastric slow waves and animal behavior were monitored in the fasting state at baseline and with various parameters of AES. RESULTS: (1) AES at tachygastric frequencies (7-14 cpm) significantly reduced the percentage of normal 4- to 6-cpm slow waves and induced tachygastria; (2) AES significantly and substantially inhibited the antral motility in the fed state; (3) AES in the fasting state energy dependently induced symptoms, and the symptom score was linearly correlated with the stimulation frequency, and (4) there was a significant negative correlation between percentage of tachygastria and index of antral motility. CONCLUSIONS: AES induces tachygastria and inhibits the antral motility. Tachygastria is correlated with antral motility.     

An Evaluation of Adult Electrogastrography Criteria in Healthy Children

The current study examined whether electrogastrogram (EGG) recordings obtained from healthy children would be considered normal by standards established for adults and whether EGG patterns differ between children/adolescents and adults. Twenty-eight healthy children (54% females; ages 8–17 years; mean = 12.4 years) were evaluated and compared to 15 healthy adults evaluated previously. EGGs were recorded for 30 min in the fasting state and for 1 hr following a standard meal. For both pediatric and adult participants, there was a significant increase in both the dominant frequency and the dominant power from the pre- to the postprandial period (P < 0.001 for each). Using adult standards, the percentage normal slow waves was ≥70% of the recording time in 96% of children in the fasting state and in 100% in the postprandial period. A postprandial power increase was seen in 89% of the children. In conclusion, our data indicate that American Motility Society (AMS) consensus adult criteria for a normal EGG are appropriate to apply to children and adolescents when utilizing methodology and meal challenge similar to those used to establish the adult norms.     

Correlation between gastric myoelectrical activity recorded by multi-channel electrogastrography and gastric emptying in patients with functional dyspepsia

OBJECTIVE: To investigate the correlation between the parameters of multi-channel electrogastrography (MEGG) and gastric emptying in patients with functional dyspepsia. MATERIAL AND METHODS: The MEGG study included 19 patients with functional dyspepsia and 19 healthy subjects. MEGG was recorded for 30 min in the fasting state and 60 min after a standard test meal (450 kcal). MEGG parameters included the power ratio (PR), the normal percentage of 2-4 cpm gastric slow waves (N%) and the percentage of slow wave coupling (%SWC). Gastric emptying was measured in the 19 patients by SPECT (single photon emission computerized tomography) and the gastric emptying parameters included lag phase (LP), half time of gastric emptying (T1/2), emptying rate of stable phase (ERSP), one hour retention rate (1HRR), and two hour retention rate (2HRR). RESULTS: No significant difference in MEGG parameters was found between normal subjects and patients. There was a significant negative correlation between postprandial N% and LP (r = - 0.52, p<0.05) and a significant negative correlation between fasting %SWC and 1HRR (r = - 0.48, p<0.04) or 2HRR (r = - 0.48, p<0.05). Compared with the patients in the PR > 1 group, patients in the PR < or = 1 group had significantly higher T1/2 and 2HRR but lower ERSP. CONCLUSIONS: Both the temporal regularity and spatial regularity of gastric slow waves have negative correlations with gastric emptying, which suggests that the impaired gastric myoelectrical activity may be responsible for the delayed gastric emptying in patients with functional dyspepsia.     

Inhibitory effects of various types of stress on gastric tone and gastric myoelectrical activity in dogs

Objective. Stress impairs gastrointestinal motility, causing, for example, delayed gastric emptying and altered intestinal transit. However, little is known about the effect of various stress factors on gastric tone and gastric myoelectrical activity (GMA). The aim of this study was to assess the effect of various kinds of stress on gastric tone and GMA in a canine model. Material andmethods. Six dogs, implanted with a gastric cannula and one pair of gastric seromuscular electrodes, were studied. Three kinds of stress (visual, thermal, or audio stimulation) were applied in separate sessions. GMA and gastric tone were recorded for 30 min at baseline and 30 min during stress. Results. Visual stress (blinding) did not alter gastric tone or GMA; cold stress (ice water) and audio stress (loud noise) significantly inhibited gastric tone: gastric volume was increased from 107.2±13.5 ml at baseline to 135.6±23.8 ml with cold stress (p=0.041), and from 106.4±5.7 ml at baseline to 159.2±15.1 ml with audio stress (p=0.007). Although the dominant frequency or power of gastric slow waves was not altered, the percentage of normal gastric slow waves was markedly reduced from 98.3±0.8 to 87.5±3.7 with cold stress and from 90.2±3.3 to 80.6±2.9 with audio stress (p<0.05). Conclusions. Cold- and audio stress inhibit gastric tone and impair gastric slow waves, whereas visual stress does not seem to have such effects. These findings will help to increase our understanding of gastrointestinal motor disorders related to stress.     

Effect of two-channel gastric electrical stimulation with trains of pulses on gastric motility

AIM： To investigate the effect of two-channel gastric electrical stimulation （GES） with trains of pulses on gastric emptying and slow waves.METHODS： Seven dogs implanted with four pairs of electrodes and equipped with a duodenal cannula were involved in this study. Two experiments were performed.The first experiment included a series of sessions in the fasting state with trains of short or long pulses, each lasted 10 min. A 5-min recording without pacing was made between two sessions. The second experiment was performed in three sessions （control, single-channel GES, and two-channel GES）. The stimulus was applied via the 1st pair of electrodes for single-channel GES （GES via one pair of electrodes located at 14 cm above the pylorus）, and simultaneously via the 1st and 3rd channels for two-channel GES （GES via two pairs of electrodes located at 6 and 14 cm above the pylorus）, Gastric liquid emptying was collected every 15 min via the cannula for 90 min.RESULTS： GES with trains of pulses at a pulse width of 4 ms or higher was able to entrain gastric slow waves. Two-channel GES was about 50% more efficient than single-channel GES in entraining gastric slow waves. Two-channel but not single-channel GES with trains of pulses was capable of accelerating gastric emptying in healthy dogs. Compared with the control session, two-channel GES significantly increased gastric emptying of liquids at 15 rain （79.0% ± 6.4% vs 61.3% ± 6.1%, P 〈 0.01）, 30 min （83.2% ± 6.3 % vs 68.2% ± 6.9%, P 〈 0.01）, 60 min （86.9% ± 5.5 % vs 74.1% ± 5.9%, P 〈 0.01）, and 90 rain （91.0% ± 3.4% vs 76.5% ± 5.9%, P 〈 0.01）.CONCLUSION： Two-channel GES with trains of pulses accelerates gastric emptying in healthy dogs and may have a therapeutic potential for the treatment of gastric motility disorders.     

Abnormal gastric myoelectrical activity and delayed gastric emptying in patients with symptoms suggestive of gastroparesis

Gastric myoelectrical activity modulates gastric motor activity. Abnormalities in gastric myoelectrical activity may be associated with gastric motility disorders. The aim of this study was to investigate the correlation of gastric myoelectrical activity with gastric emptying in symptomatic patients with and without gastroparesis. Ninety-seven patients with symptoms suggestive of gastroparesis participated in the study. Gastric myoelectrical activity was recorded using surface electrogastrography. The electrogastrogram (EGG) was recorded for 30 min in the fasting state and for 120 min after a solid test meal. Gastric emptying of the solid meal was simultaneously monitored for 120 min. Patients with delayed gastric emptying showed a significantly lower percentage of normal gastric slow waves (P<0.03) and a significantly reduced increase of the dominant power in the postprandial EGG (P<0.02). Postprandial EGG parameters were found to be able to predict delayed emptying of the stomach. Postprandial gastric dysrhythmia predicts delayed gastric emptying with an accuracy of 78%, while the abnormality in postprandial EGG power predicts delayed gastric emptying with an accuracy of 75%. All patients with abnormalities in both the rhythmicity and the power had delayed gastric emptying. Patients with delayed gastric emptying have a lower percentage of normal gastric slow waves in the EGG and a lower postprandial increase in the dominant power. Abnormalities in the postprandial EGG seem to be able to predict delayed emptying of the stomach. However, a normal EGG does not seem to guarantee normal emptying of the stomach.     

Impaired Gastric Myoelectrical Activity in Patients with Chronic Renal Failure

Dysmotility and delayed emptying of the stomachhave been reported in patients with chronic renalfailure (CRF). The aim of this study was to investigatewhether gastric myoelectrical activity was impaired in patients with CRF using electrogastrography.The electrogastrogram (EGG) was recorded in 24symptomatic patients with CRF (15 with diabetes) and 12normal subjects. Two 30-min EGG recordings before and after a test meal were analyzed using spectralanalysis methods. It was found that patients with CRFshowed a significantly lower percentage of normal 2-4cpm slow waves in both fasting and fed states in comparison with healthy controls (in fastingstate: 88.9 ± 2.5% vs 67.4 ± 6.6%/63.27.0%, P < 0.01; in fed state: 89.6 ± 1.8% vs64.6 ± 6.2%/62.0 ± 8.3%, P < 0.01;controls vs diabetic patients/nondiabetic patients). Both patient groups showed a significantlyhigher prevalence of the abnormal EGG, which was definedas the percentage of 2-4 cpm slow waves lower than 70%(fasting state: 8% vs 60%/56%, P < 0.01/0.05; fed state: 0% vs 53%/56%, P < 0.005/0.002;controls vs diabetic patients/nondiabetic patients). Nosignificant difference was observed in the regularity ofthe gastric slow waves between the two patient groups. The healthy controls showed a significantincrease in the dominant power and frequency of the EGGafter the test meal. However, this increase was absentin the two patient groups. It was concluded that patients with chronic renal failure haveabnormal gastric myoelectrical activity, includingimpaired regularity of the gastric slow wave and afailed increase in the power of the EGG at 3 cpm.Electrogastrography is an attractive noninvasive method for thestudy of gastric motility in patients with severechronic renal failure.     

Inhibitory effects of cholecystokinin on postprandial gastric myoelectrical activity

While a number of studies have investigated the effects of cholecystokinin (CCK) on gastrointestinal motility, little is known on the effects of CCK on gastric myoelectrical activity, which regulates gastric motility. The aim of this study was to investigate the effects of intravenous infusion of CCK-8 on gastric myoelectrical activity in normal humans. Gastric myoelectrical activity was measured in 10 healthy subjects with a noninvasive electrogastrographic technique by placing abdominal electrodes on the epigastric area. Two study sessions were performed in each subject on two separate days with double-blinded infusion of either saline or CCK (24 pmol/kg/hr). The procedure for each session was as follows: (A) 30-min baseline fasting electrogastrogram (EGG); (B) start infusion, another 30-min EGG; (C) give meal, 60-min EGG; and (D) stop infusion, another 60-min EGG. The dominant frequency and peak power (amplitude) of the EGG, and the percentage of normal 2–4 cycles/min slow waves during each recording session were computed and compared between placebo and CCK. It was found that normal 3 cpm slow waves were recorded in all EGGs. Infusion of CCK had no effect on the frequency of the gastric slow wave and did not induce gastric dysrhythmias. It was also found that intravenous infusion of CCK significantly decreased the EGG peak power (amplitude) during the first hour after the meal (the infusion was given during this period) in comparison with placebo (P<0.05). This inhibitory effect on EGG peak power was sustained but not significant during the second postprandial hour (the infusion was not given during this period). It was concluded that intravenous infusion of CCK at a physiological concentration significantly decreased the postprandial EGG amplitude in normal humans, suggesting an inhibitory effect on postprandial gastric motility, but did not change the frequency and regularity of the gastric slow wave.     

埋置胃肌电起搏电极后胃肌电活动演变的研究

目的探讨胃埋置电起搏电极后胃肌电活动演变过程。方法7条纯种比格犬,每1条犬通过开腹手术沿胃大弯浆膜层埋置4对心脏起搏电极。术后第1天开始记录进食固体食物(200g/只)前后30min胃慢波,连续记录7d后,间隔3周再次用同样方法记录胃肌电活动1次。结果(1)与术后第1天相比,术后第2天的空腹正常胃慢波百分率无明显改变(P>0.05)。而术后第3、4、5、6、7天明显降低(P<0.05)。(2)从术后第1天至第7天,与相应天数的空腹胃慢波相比,进食后正常胃慢波百分率增加(P<0.05),主功增高(P<0.05)。(3)手术后第3周,所有犬的进食前后正常胃慢波百分率均>70%。与空腹胃慢波相比,进食后主功增加(P<0.05)。结论犬胃埋置胃肌电起搏电极后胃肌电紊乱在术后第3天出现,之后逐步恢复。进食后胃肌电紊乱改善的特征是否预示胃肌电紊乱能够恢复正常尚待明确。     

Is There a One-to-One Correlation Between Gastric Emptying of Liquids and Gastric Myoelectrical or Motor Activity in Dogs?

The aim of this study was to investigate the correlation of gastric emptying with gastric myoelectrical activity recorded from internal serosal electrodes and with gastric motility measured from strain gauges. The study was performed in eight healthy dogs chronically implanted with four pairs of electrodes and two strain gauges on the gastric serosa and equipped with a duodenal fistula for the assessment of gastric emptying. Each dog was fed four liquid test meals on four separate days with identical calories (320 kcal) and volume (473 ml). A correlation was found between gastric emptying and the energy of contraction in the frequency band of 3.75–7.50 cycles/min during the first 30 min after the meal (r = 0.46, P < 0.05). While none of the parameters of gastric myoelectrical activity was correlated with gastric emptying, two major parameters, percentage of regular gastric slow waves and percentage of slow-wave coupling, were found to be associated with delayed gastric emptying. A significant correlation was found between the frequency of gastric slow waves and that of the contractions in both fasting (r = 0.83, P < 0.001) and fed state (r = 0.70, P < 0.001 at 30 min, r = 0.86, P < 0.001 at 60 min). It was concluded that gastric emptying is correlated with the strength of gastric contractions in a frequency range identical to that of the gastric slow waves, and there is no one-to-one correlation between gastric emptying of liquids and any parameters of gastric myoelectrical activity. However, major parameters of gastric myoelectrical activity are associated with gastric emptying.     

Effects of Sibutramine on Gastric Emptying, Intestinal Motility and Rectal Tone in Dogs

The aim of this study was to evaluate the effects of sibutramine on gastric emptying, small-bowel contractions, rectal tone and compliance, and gastrointestinal myoelectrical activity. The study was performed in 14 dogs. It was composed of three separate experiments: gastric emptying of liquids and gastrointestinal slow waves; small-bowel contractions; and rectal tone and rectal compliance. Each experiment included two sessions: a control session and a treatment session with sibutramine (5 mg/kg orally) administrated 2 h before the study. Sibutramine significantly accelerated liquid gastric emptying at 75 and 90 min after the meal but did not alter gastrointestinal slow waves. Gastric emptying at 75 and 90 min was 61.42 ± 7.71 and 66.32 ± 7.67% in the control session, and increased to 71.27 ± 5.14 and 75.93 ± 5.29% in the session with sibutramine (p < 0.05, vs. control). Sibutramine significantly inhibited postprandial small-bowel contractions. Sibutramine did not alter the rectal tone, but significantly increased rectal compliance. Sibutramine accelerates gastric emptying of liquids but inhibits small-bowel contractions. These findings suggest the peripheral mechanisms of sibutramine in reducing food intake and causing weight loss in obesity patients.     

Gallbladder and gastric motility in obese newborns, pre-adolescents and adults

Background and Aim: Impaired gallbladder and gastric motility have been associated with obesity in adults. The timing of appearance of this dysfunction, however, is unclear. Methods: Lean and obese subjects from three different age groups were studied noninvasively: 50 newborns (1–12 months old, six obese), 18 pre‐adolescents (7–8 years old, seven obese), and 99 adults (22–80 years old, 32 obese) classified according to standard normal tables and body mass index. Changes of fasting/postprandial gallbladder and gastric motility were assessed simultaneously by functional ultrasonography in response to milk (newborns and pre‐adolescents) and to a liquid test meal (adults). Results: In newborns, fasting and postprandial gallbladder volumes and gastric emptying were similar between obese and lean subjects. In pre‐adolescents, obese subjects had a larger fasting gallbladder volume, with slower postprandial gastric emptying than lean subjects. In obese adults, the most evident dysfunction emerged, with larger fasting and postprandial residual gallbladder volume, and slower postprandial gastric emptying than lean subjects. Conclusions: Obese subjects display abnormal gallbladder and gastric motility patterns, which first appear in pre‐adolescents and deteriorate in adults. Such abnormalities are absent in obese newborns. Functional ultrasonography can detect altered cholecysto‐gastric motility at the earliest stage. Our findings suggest an age‐related decline of motility, probably secondary to excessive fat and insulin‐resistance.     

Characterization of Gastric Myoelectrical Rhythms in Patients with Systemic Sclerosis Using Multichannel Surface Electrogastrography

The aim of this study was to characterize multichannel surface electrogastrography (EGG) recordings in patients with systemic sclerosis (scleroderma, SSc) compared to normal controls. Ten SSc patients and 13 healthy age-matched controls were enrolled in this study. Gastric myoelectrical activity was recorded using a four-channel electrogastrograph with abdominal surface electrodes. The EGG was recorded in the morning for 1 hr in the fasting state, and 1 hr after a standardized (500 kcal) test meal. It was found that: (1) The regularity of the gastric slow wave was significantly lower in the SSc patients when compared with the normal controls in both fasting and fed states. (2) There was a significantly higher incidence of bradygastria in the SSc patients. (3) The SSc patients showed a significantly lower percentage of slow wave coupling among the four-channel EGGs than the controls. (4) In comparison with the controls, the patients showed an impaired spatial distribution of gastric slow wave power in both fasting and fed states and an impaired spatial distribution of slow wave frequency in the fasting state. It was concluded that SSc patients have an abnormal gastric slow wave as shown in the multichannel EGG as a decreased percentage of normal slow waves and impaired spatial coordination of gastric slow waves. The multichannel EGG may serve as a simple, noninvasive, and cost-effective method to assess gastric motility disorders and their relevance in patients with SSc.