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.     

Experimental gastric dysrhythmias and its correlation with in vivo gastric muscle contractions

AIM: To study the direct correlation between gastric dysrhythmias and in vivo gastric muscle tone. METHODS: Five healthy dogs were implanted with 4 pairs of electrodes along the greater curvature, with a strain gauge (SG) being sutured parallel to the distal electrodes (2 cm above the pylorus). Intravenous vasopressin was given to induce gastric dysrhythmia. The percentage of regular slow waves and SG energy were calculated. RESULTS: (1) the regularity of gastric myoelectric activity (GMA) was reduced during and after infusion of vasopressin; (2) SG energy was significantly decreased during the infusion of vasopressin; (3) the decrease in SG energy was well correlated with the reduction in GMA regularity; (4) SG energy was negatively correlated with bradygastria and tachygastria. CONCLUSION: Vasopressin inhibits gastric contractions and impairs gastric slow waves; gastric dysrhythmias are associated with the reduced antral muscle contractions, and are indicative of antral hypomotility.     

正向低频长脉冲对逆向刺激模拟胃异位起搏点诱发胃电过速的治疗作用

目的探讨正向低频长脉冲胃电刺激对逆向高频长脉冲模拟胃异位起搏点诱发胃电过速的治疗作用。方法7条纯种雌性比格犬，依次沿胃大弯前壁浆膜层植入4对心脏起搏电极。通过距离幽门最近的1对电极输入高频长脉冲电信号诱导内源性胃肌电活动发生胃电过速，刺激参数为0．3mA、300ms、9cpm。刺激10min后，通过距离口端最近的1对电极输入不同振幅的低频长脉冲，直至纠正胃电过速，从而获得正向控制胃电过速的最小能量。观察电刺激前、刺激中和刺激后消化不良症状并进行评分。结果正向低频长脉冲能够完全控制逆向高频长脉冲模拟异位起搏点诱发的胃电过速，最小刺激振幅为（5．0±0．93）mA，最小刺激能量为（1500±277．75）（ms×mA）。获得完全控制的正向低频长脉冲与逆向高频长脉冲相比，正常胃慢波百分率升高（95．61％±3．78％ vs42．68％±19．74％，P=0．001），胃电过速百分率降低（3．58％±0．85％ vs40．29％±19．68％，P=0．001），主频降低（6．35±0．66 vs5．60±0．85，P=0．031），主功升高（-9．67±5．08 vs-2．26±1．03，P=0．001）。胃慢波基线期、高频长脉冲（RG-ES）期、完全控制的低频长脉冲（FGES＋RGES）期的消化不良症状评分均为1分，无明显差异。结论正向低频长脉冲能够完全纠正由高频逆向长脉冲模拟人工 异位起搏点引发的胃电过速，并恢复由此降低的胃动力。     

Psychosocial distress is associated with abnormal gastric myoelectrical activity in patients with functional dyspepsia

OBJECTIVE: Functional dyspepsia (FD) is a heterogeneous and loosely defined clinical syndrome that is characterized by persistent or recurrent abdominal pain or discomfort centered in the upper abdomen without any identifiable structural or biochemical basis. Gastric myoelectrical activity in functional dyspepsia patients with gastric reddish streaks as a subgroup has not previously been investigated and the potential role of psychosocial distress in the genesis of gastric dysrhythmia in patients with FD is unclear. MATERIAL AND METHODS: Electrogastrography was performed in 45 patients with FD and 35 healthy controls for 30 min in the fasting state and 30 min postprandially. Psychological distress and the number and severity of stressful life events were measured using self-rating questionnaires. RESULTS: FD patients had a higher percentage of pre- and postprandial dysrhythmia, lower dominant frequency, and a higher instability coefficient as compared to healthy controls. In FD patients, severity of stressful life events was positively correlated with the percentage of tachygastria in the fasting state (r=0.43, p=0.005) and marginally positively correlated with the percentage of postprandial tachygastria (r=0.253, p=0.098) and instability coefficient of the dominant frequency (r=0.256, p=0.093). Total number of stressful life events was marginally positively correlated with fasting tachygastria (r=0.25, p=0.098) and instability coefficient of the postprandial dominant frequency (r=0.287, p=0.056). Interpersonal sensitivity was found to be negatively correlated with fasting dominant frequency in FD patients (r= - 0.311, p<0.05). CONCLUSIONS: FD patients with gastric reddish streaks have abnormal fasting and postprandial gastric myoelectrical activity. Perceived severity of stressful life events and interpersonal sensitivity are associated with disturbance of gastric myoelectrical activity.     

功能性消化不良患者胃肌电紊乱的发生率

背景：功能性消化不良（FD）的病理生理机制尚未完全阐明，消化道运动功能异常可能是主要发病机制之一。目的：通过胃电图检查探讨FD患者胃肌电紊乱的发生率，证实胃动力异常在FD发生中的作用。方法：368例FD患者行餐前和餐后体表胃电图榆查，对正常胃慢波百分比和胃电主功率两项参数进行分析。结果：根据正常胃慢波百分比，本组FD患者可分为胃电节律正常组（43．2％）、胃动过缓组（33．2％）、胃动过速组（6．2％）和混合性胃电节律紊乱组（17．4％）。在胃电节律正常的FD患者中，34．0％（54例）存在餐后／餐前胃电主功率比异常。结论：本组71．5％的FD患者存在胃肌电紊乱，证实胃动力异常在FD的发病机制中起有重要作用。     

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.     

Pyloric electrical stimulation reduces food intake by inhibiting gastric motility in dogs

BACKGROUND & AIMS: The pylorus plays an important role in regulating gastric emptying. The aim of this study was to investigate the therapeutic potential of pyloric electrical stimulation (PES) for obesity in dogs. METHODS: The study was composed of 3 separate experiments. The first experiment was designed to study the effects of PES with various parameters on gastric emptying and gastric slow waves in 5 sessions. The second experiment was used to test the effects of PES on antral contractions. The acute effect of PES on food intake was studied in the third experiment. RESULTS: (1) Pyloric myoelectrical recording showed dual frequencies. The lower frequency was identical to the frequency of the gastric slow waves, and the higher frequency was similar to that of the intestinal slow waves. (2) Gastric emptying was significantly delayed with PES, and the delay in gastric emptying was significantly and negatively correlated with stimulation energy ( r = -.673; P < .001). (3) PES significantly impaired the regularity and coupling of the intrinsic gastric myoelectrical activity in an energy-dependent manner. The delayed gastric emptying was significantly correlated with the impairment of the coupling of gastric myoelectrical activity ( r = .441; P < .02). (4) Antral contractions on the fed state were significantly and substantially inhibited with PES. (5) Acute PES significantly reduced food intake. CONCLUSIONS: PES reduces food intake that may be attributed to its inhibitory effects on intrinsic gastric myoelectrical activity, antral contractions, and gastric emptying.     

Effect of cisapride on myoelectrical and motor responses of antropyloroduodenal region during intraduodenal lipid and antral tachygastria in conscious dog

The myoelectrical and motor response of the antropyloroduodenal region to intraduodenal nutrient stimulation or antral tachygastria represent useful models for, respectively, physiological and pathophysiological gastric stasis to test the efficacy of prokinetic drugs. We evaluated the effects of an intravenous bolus of cisapride (0.63 mg/kg) on the myoelectrical and motor response of the antropyloroduodenal region to an intraduodenal triglyceride emulsion (10% Intralipid, 0.5 ml/min) or antral tachygastria in conscious dogs. Intraduodenal lipid suppressed antral motility (P<0.05, compared to intraduodenal saline) and stimulated phasic pyloric contractions (P<0.01, compared to intraduodenal saline), a motor pattern known to be associated with delayed gastric emptying. During intraduodenal lipid stimulation cisapride virtually abolished all isolated pyloric motor events (P < 0.05) and stimulated antral and duodenal motility (P<0.05 for both) and antropyloroduodenal coordination (65% versus 15%;P<0.05). Antral tachygastria was associated with a higher number of isolated pyloric motor events in the fasted state [0.8 (0.7–1.1) per minute versus 0.2 (0–0.3) per minute;P<0.05], but not during intraduodenal lipid stimulation [1.1 (0.9–1.7) per minute versus 1.2 (1.0–1.9) per minute; NS]. Cisapride decreased the number and duration of spontaneous episodes of antral tachygastria during intraduodenal saline and lipid infusion (P<0.05 for both) and abolished the tachygastria-associated motor patterns. Cisapride induced a 20% decrease in the antral slow-wave frequency during intraduodenal saline and lipid, irrespective of gastric pacemaker rhythm. We conclude that: (1) cisapride overcomes feedback from small intestinal lipid receptors on myoelectrical and motor activities of the antropyloroduodenal region and decreases antral slow-wave frequency, and (2) cisapride inhibits antral tachygastria and tachygastria-associated motor patterns. These effects may contribute to the effective gastrokinetic properties of cisapride in physiological and certain forms of pathophysiological gastric stasis.This study was supported by a grant from the Netherlands Organization for Research, Council for Medical Research (NWO-GBMW; grant 900-522-082). Part of the results of this study were presented in abstract form at the Annual Meeting of the American Gastroenterological Association held in New Orleans (Gastroenterology 100:A440, 1991).     

Improvement of gastric motility with gastric electrical stimulation in STZ-induced diabetic rats

AIMS: The aims of this study were to observe whether gastric motility was impaired in streptozotocin (STZ)-induced diabetic rats and whether gastric electrical stimulation was able to restore the impaired motility. METHODS: Ten control rats and 30 STZ-induced diabetic rats were used in this study. Gastric slow waves were recorded at baseline and 0, 1, 2, 3 and 4 weeks after the injection of STZ or vehicle. Gastric emptying with (long or short pulses) or without gastric electrical stimulation was measured 6 weeks after STZ injection in a group of 10 diabetic rats each. RESULTS: (1) STZ injection resulted in hyperglycemia and weight loss. (2) Gastric motility was impaired in the diabetic rats. The percentage of normal slow waves was progressively reduced 2 weeks after STZ injection. Compared with the control rats, gastric emptying in the diabetic rats was significantly delayed 6 weeks after STZ injection (60 +/- 3 vs. 79 +/- 2%, p < 0.02). (3) Gastric electrical stimulation with either long or short pulses accelerated gastric emptying in the diabetic rats. (4) Gastric electrical stimulation with long but not short pulses was capable of normalizing gastric dysrhythmia in the diabetic rats. CONCLUSION: Our data show that gastric motility is impaired in STZ-induced diabetic rats as reflected by a progressive reduction in the percentage of normal gastric slow waves and delayed gastric emptying. Moreover, here we show that gastric electrical stimulation normalizes delayed gastric emptying in diabetic rats and this normalization is not attributed to the effect of gastric electrical stimulation on gastric slow waves.     

Effects of Octreotide and Erythromycin on Gastric Myoelectrical and Motor Activities in Patients with Gastroparesis

Simultaneous recordings of gastric manometry andmyoelectrical activity were made in 10 patients withgastroparesis. Intravenous erythromycin (100 mg) wasadministered in the fasting state for a period of 30 min. Subcutaneous injection of octreotide(100 g) was administered before one of the fouridentical test meals. It was found that octreotidesignificantly decreased the antral motility index(30-min fasting: 4.51 ± 1.04 vs 1.75 ±0.97, P < 0.02; 60-min fed: 5.16 ± 1.44 vs 3.4± 1.41, P < 0.05) and the dominant power ofthe EGG (fasting power: 35.19 ± 1.54 vs 30.84± 1.57 dB, P < 0.004; postprandial powerincrease: 5.52 ± 1.06 vs 0.27 ± 0.87, P< 0.001). Erythromycin significantly increased theantral motility index (3.16 ± 0.96 vs 9.5± 0.61, P < 0.001) and the dominant power ofthe EGG (28.86 ± 1.57 dB vs 33.55 ± 1.59dB, P < 0.005) in the fasting state. An improvement in theregularity of the gastric slow wave was also noted witherythromycin. It was concluded that: (1) the inhibitoryeffect of octreotide on postprandial gastric motility and myoelectrical activity suggests thatcaution should be exercised when octreotide is used inpatients with gastroparesis; and (2) the stimulatoryeffect of erythromycin on gastric myoelectrical activity may enhance gastric motility and gastricemptying in patients with gastroparesis.     

Impaired gastric slow waves induced by spatial disorientation and effect of domperidone

OBJECTIVES: Our aims were to investigate the dominant frequency and regularity of gastric myoelectrical activity during motion sickness induced with the advanced spatial disorientation demonstrator (ASDD) and to evaluate the effect of domperidone on gastric myoelectrical activity and gastrointestinal symptoms during motion sickness. METHODS: Thirteen healthy volunteers participated in this study. This study was executed using the ASDD, which could duplicate several spatial disorientation phenomena in a safe, controlled environment. Each subject participated in two sessions and received oral administration of 10 mg domperidone before the study in one of the sessions. In each session, three 15-min EGG recordings were made before, during, and after rotation. The symptoms were scored by Graybiel's scale of motion sickness before and after rotation. All EGG data were subjected to computerized spectral analysis to obtain the percentage of normal 2-4 cycles/min (cpm) slow waves, percentage of tachygastria, EGG dominant frequency and power, and instability coefficient of the dominant frequency. RESULTS: We have found that the percentage of normal gastric slow wave was decreased (control session: 86.2 +/- 4.0% vs 70.0 +/- 5.4%, p < 0.01; domperidone session: 82.7 +/- 4.6% vs 69.8 +/- 5.6%, p < 0.03) and the percentage of tachygastria was increased (control session: 8.7 +/- 3.2% vs 17.8 +/- 5.6%, p < 0.01; domperidone session: 9.2 +/- 3.3% vs 18.1 +/- 3.5%, p < 0.01) after rotation in both sessions. The minute-by-minute variation of the gastric slow wave frequency was significantly increased during rotation in both sessions (control: 0.74 +/- 0.16 vs 1.35 +/- 0.19, p < 0.01; domperidone: 0.90 +/- 0.20 vs 1.47 +/- 0.17, p < 0.01). Domperidone did not prevent dysrhythmia or the symptoms of motion sickness. CONCLUSIONS: The percentage of normal gastric slow waves is decreased and the percentage of tachygastria is increased with spatial disorientation. Domperidone does not prevent gastric dysrhythmia or the symptoms of motion sickness induced with spatial disorientation.     

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.     

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.     

Comparison of Gastric Electrical Activity and Gastric Emptying in Healthy and Dyspeptic Children

To assess and compare gastric electrical activity and gastric emptying recorded from dyspeptic and healthy children, cutaneous electrogastrography and ultrasound examination of the gastric emptying were simultaneously performed in 52 children with nonulcer dyspepsia and 114 healthy children. Symptoms were scored from 0 (none) to 6 (severe). A higher percentage of tachygastria, a higher instability of gastric power, and a lower post/preprandial ratio were present in dyspeptic children than healthy children. As regards the ultrasound parameters, the fasting antral area and T1/2 were similar in dyspeptic children and controls. Only 32% of dyspeptic children had a normal gastric emptying time vs 66% of healthy children. Marked postprandial antral dilatation was found in the dyspeptic children, which correlated with the total symptom score. Electrogastrographic and gastric emptying parameters show specific differences in dyspeptic children with respect to controls, both fasting and after a meal. The postprandial antral distension correlates with the severity of the symptoms.     

Cholinergic effects on human gastric motility

BACKGROUND: Cholinergic regulation of chronotropic (frequency) and inotropic (force) aspects of antral contractility and how these impact on gastric emptying are not well delineated. AIMS: To determine the effects of cholinergic stimulation and inhibition on myoelectric, contractile, and emptying parameters of gastric motility. METHODS: Ten normal subjects underwent three studies each, using simultaneous electrogastrography (EGG), antroduodenal manometry, and gastric emptying with dynamic antral scintigraphy (DAS). After 30 minutes of baseline fasting manometry and EGG, subjects received saline intravenously, atropine (0.6 mg then 0.25 mg/hour intravenously), or bethanechol (5 mg subcutaneously). This was followed by another 30 minutes' recording and by three hours of postprandial recording after ingestion of a technetium-99m labelled solid meal. RESULTS: During fasting, atropine decreased, whereas bethanechol increased, the antral manometric motility index and EGG power. Postprandially, atropine decreased the amplitude of antral contractions by DAS, decreased the postprandial antral manometric motility index, and slowed gastric emptying. Atropine caused a slight increase in postprandial frequency of antral contractions by DAS and gastric myoelectrical activity by EGG. Bethanechol slightly increased the amplitude, but slightly decreased the frequency of antral contractions by DAS and decreased the frequency of gastric myoelectrical activity by EGG, with no significant increase in the motility index or gastric emptying. CONCLUSIONS: Cholinergic antagonism with atropine reduces antral contractility and slows gastric emptying. Cholinergic stimulation with bethanechol increases antral contractility, but decreases the frequency of antral contractions, without altering the antral motility index or gastric emptying.     

Antral Inflammatory Cells,Gastric Emptying,and Electrogastrography in Pediatric Functional Dyspepsia

The aims of the current study were to determine the activation states of antral eosinophils and mast cells and to evaluate the interactions of antral inflammatory cells with gastric emptying and electrogastrography (EGG) in 30 pediatric patients with functional dyspepsia. Eosinophil degranulation was moderate in 42% and extensive in 54% of patients. Mast cell degranulation was >50% in 81% of patients. Elevated mast cell density was associated with slower one hour gastric emptying and increased preprandial dysrhythmia. Mast cell density correlated with the preprandial percentage tachygastria. CD3+ cell density correlated with the preprandial percentage tachygastria also, but only in patients with increased eosinophil density. In conclusion, antral eosinophils and mast cells are significantly activated in pediatric functional dyspepsia. Mast cell density is associated with delayed gastric emptying and preprandial dysrhythmia, suggesting that there may be an interaction between antral inflammation and gastric electromechanical dysfunction in the pathophysiology of pediatric functional dyspepsia.     

Identification of Gastric Contractions from Cutaneous Electrogastrogram

Objective : The objective of this study was to investigate whether gastric contractions in the fasting and fed state can be identifled from the cutaneous electrogastro-gram. Methods : Simultaneous measurements of gastric myoelectrical and manometric activities were made in 10 healthy female volunteers from 1:00 AM to 9:45 AM. For manometric recording, a catheter incorporating solid state transducers was used. Cutaneous electro-gastrography (EGG) was used for myoelectrical recording. All EGG data from 1:00 AM to 7:30 AM that occurred during motor quiescence, all EGG data that occurred during antral contractions, and 2-h EGG data after breakfast given at 7:30 AM were quantitatively analyzed and compared with each other. The EGG in three specific periods (fasting without antral contractions, fasting with contractions, and postprandial) was characterized by four parameters that include frequency, power, and stabilities of the frequency and power. Results: 1 ) the peak power of the postprandial EGG was, respectively, 12.5 dB (about 2-fold increase n i amplitude) and 6.8 dB (ahout 1-fold increase in amplitude) higher than that during motor quiescence (p < 0.05) and motor activity in the fasting state; 2) the dominant frequency of the postprandial EGG was, respectively, 6% and 13% higher than that during motor quiescence and motor activity (p < 0.05) in the fasting state; 3) the peak power of the fasting EGG was 48% more unstable during motor activity than motor quiescence (p < 0.05); 4) the stability of the EGG frequency was not significantly different during the three different periods. Conclusion : The EGG provides important and useful information for the assessment of gastric motility. An unstable EGG peak power is indicative of gastric contractions in the fasting state. An increase in EGG peak power and/or dominant frequency after a solid test meal suggests a normal postprandial gastric motility.     

Synchronous electrogastrographic and manometric study of the stomach as an esophageal substitute

AIM: To investigate the electric and contractile mechanisms involved in the deranged function of the transposed stomach in relation to the course of the symptoms and the changes in contractile and electrical parameters over time. METHODS: Twenty-one patients after subtotal esoph agectomy and 18 healthy volunteers were studied. Complaints were compiled by using a questionnaire, and a symptom score was formed. Synchronous electrogas trography and gastric manometry were performed in the fasting state and postprandially. RESULTS: Eight of the operated patients were symptom-free and 13 had symptoms. The durations of the postoperative periods for the symptomatic (9.1±6.5 mo) and the asymptomatic (28.3±8.8 mo) patients were significantly different. The symptom score correlated negatively with the time that had elapsed since the operation. The percentages of the dominant frequency in the normogastric, bradygastric and tachygastric ranges differed significantly between the controls and the patients. A significant difference was detected between the power ratio of the controls and that of the patients. The occurrence of tachygastria in the symptomatic and the symptom-free patients correlated negatively both with the time that had elapsed and with the symptom score. There was a significant increase in motility index after feeding in the controls, but not in the patients. The contractile activity of the stomach increased both in the controls and in the symptom-free patients. In contrast, in the group of symptomatic patients, the contractile activity decreased postprandially as compared with the fasting state. CONCLUSION: The patients' post-operative complaints and symptoms change during the post-operative period and correlate with the parameters of the myoelectric and contractile activities of the stomach. Tachygastria seems to be the major pathoGenetic factor involved in the contractile dysfunction.     

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.