Long-pulse gastric electrical stimulation at tachygastrial frequency reduces food intake by inhibiting proximal gastric tone

Objective. To investigate the effects of long pulse gastric electrical stimulation (GES) at a tachygastrial frequency on food intake, gastric tone and gastric myoelectrical activity (GMA). Material and methods. Of twelve dogs implanted with electrodes and a gastric cannula, 6 underwent truncal vagotomy. Stimulus consisted of long pulses with a frequency of 9 cycles/min. Experiment one was performed in all dogs to test for food intake with or without GES. Experiment two on six normal dogs consisted of baseline, GES and recovery periods. Gastric volume and GMA were recorded. Results. 1) GES reduced food intake in both normal (398.5±111.7 g versus 573.0±97.9 g; p<0.02) and vagotomized dogs (170.6±100.4 g versus 401.0±97.3 g; p<0.05). 2) Gastric volume was increased with stimulation from 168.4±17.7 ml to 301.1±34.1 ml (p<0.02 ANOVA) and maintained at 271.8±27.6 ml. 3) The percentages of normal slow waves before, during and after GES were 83.3±4.6%, 38.0±3.5% and 61.0±12.5%, respectively (p=0.02 ANOVA). Conclusion. Long-pulse GES at tachygastrial frequency substantially reduces food intake, and is not mediated by the vagal pathway but attributed to relaxation of the stomach and impairment of intrinsic GMA.     

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.     

Gastric electrical stimulation reduces gastric tone energy dependently

OBJECTIVE: Impaired gastric accommodation is one of the major pathophysiological factors in functional dyspepsia (FD). Gastrointestinal electric stimulation (GES) as a potential therapy for treating patients with motility disorders has been applied in animal models and clinical practice. However, the response of proximal gastric tone to different GES has not been fully understood. Therefore, the aims of this study were to investigate the effects of GES with different parameters on gastric tone and to estimate the relationship between gastric volume, stimulation energy, and symptoms. MATERIAL AND METHODS: Seven dogs equipped with a gastric cannula and two pairs of serosal electrodes in the greater curvature were studied with different GES via a pair of electrodes located 10-14 cm above the pylorus. The gastric volume under constant pressure was measured using a barostat device. RESULTS: The results showed that 1) GES increased the gastric volume in a dose-dependent manner with the increase of stimulation frequency or pulse amplitude. 2) The increase in gastric volume with GES was significantly correlated to stimulation energy. 3) Mild symptoms were noted with stimulation and the score of the induced symptoms was linearly and significantly correlated with gastric volume. CONCLUSIONS: GES decreases the proximal gastric tone in an energy-dependent manner. These data suggest that GES could be used to treat patients with impaired gastric accommodation.     

Gastric electrical stimulation using endoscopically placed mucosal electrodes reduces food intake in humans

BACKGROUND: Implantable gastric stimulation (IGS) has been proposed for treating obesity. The aim of this study was to investigate the effects of temporary mucosal electrical stimulation on water and food intake as well as gastric emptying in healthy humans. METHODS: The study was designed to study the effects of temporary gastric electrical stimulation (GES) on symptoms, gastric accommodation, food intake, and gastric emptying. It was performed in 12 healthy volunteers on 3 consecutive days. GES was performed using mucosal electrodes endoscopically placed in the fundus. RESULTS: The amount of maximum water intake was reduced with GES (894 +/- 326 mL) compared with sham-GES (1,093 +/- 417 mL, p = 0.01). The food intake was also reduced with GES (p = 0.012). In comparison with sham stimulation, GES delayed gastric emptying during the first 45 min after the meal but not during the remaining time. GES with parameters effective in reducing water and food intake and delaying gastric emptying did not induce significant dyspeptic symptoms, compared with sham stimulation. CONCLUSIONS: GES using temporary mucosal electrodes decreases food intake as well as maximum intake of water, and has a tendency of delaying gastric emptying. It may have a potential application for the treatment of obesity.     

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。     

Inhibitory effects of gastric electrical stimulation on ghrelin-induced excitatory effects on gastric motility and food intake in dogs

Objective. To investigate the effects of ghrelin on food intake, gastric motility and whether gastric electrical stimulation (GES) is capable of reversing these effects of ghrelin in dogs. Material and methods. Seven healthy dogs were equipped with a gastric cannula and electrodes for the measurement of antral motility and gastric myoelectrical activity (GMA). Both food intake and gastric motility studies were performed in three sessions (control, ghrelin, 20 µg and ghrelin plus GES) in randomized order, respectively. After a 28-h fast, the animals were provided with unlimited solid food for 1.5?h, 30?min after saline or ghrelin injection. Recordings of antral contractions and GMA in each session were recorded for 30?min at baseline and 45?min after ghrelin/saline injection in the fasting state. GES was performed throughout the experiment initiated 30?min prior to the injection. Results. 1) Ghrelin significantly increased food intake from 475.6±75.5?g in the controls to 535.9±90.3?g with ghrelin (p=0.04); this excitatory effect was reversed by GES. 2) Ghrelin significantly increased the motility index from 8.6±1.6 in the controls to 16.1±2.4 with ghrelin (p=0.01) and this effect was also reversed by GES. 3). There were no effects of ghrelin on GMA. Conclusions. Ghrelin induces antral contractions and increases food intake. GES is capable of blocking these excitatory effects of ghrelin. These findings suggest that GES may inhibit the resistant effect of ghrelin on weight loss.     

Inhibitory effects of gastric electrical stimulation on ghrelin-induced excitatory effects on gastric motility and food intake in dogs

OBJECTIVE: To investigate the effects of ghrelin on food intake, gastric motility and whether gastric electrical stimulation (GES) is capable of reversing these effects of ghrelin in dogs. MATERIAL AND METHODS: Seven healthy dogs were equipped with a gastric cannula and electrodes for the measurement of antral motility and gastric myoelectrical activity (GMA). Both food intake and gastric motility studies were performed in three sessions (control, ghrelin, 20 microg and ghrelin plus GES) in randomized order, respectively. After a 28-h fast, the animals were provided with unlimited solid food for 1.5 h, 30 min after saline or ghrelin injection. Recordings of antral contractions and GMA in each session were recorded for 30 min at baseline and 45 min after ghrelin/saline injection in the fasting state. GES was performed throughout the experiment initiated 30 min prior to the injection. RESULTS: 1) Ghrelin significantly increased food intake from 475.6+/-75.5 g in the controls to 535.9+/-90.3 g with ghrelin (p=0.04); this excitatory effect was reversed by GES. 2) Ghrelin significantly increased the motility index from 8.6+/-1.6 in the controls to 16.1+/-2.4 with ghrelin (p=0.01) and this effect was also reversed by GES. 3). There were no effects of ghrelin on GMA. CONCLUSIONS: Ghrelin induces antral contractions and increases food intake. GES is capable of blocking these excitatory effects of ghrelin. These findings suggest that GES may inhibit the resistant effect of ghrelin on weight loss.     

Effects of dual pulse gastric electrical stimulation on gastric tone and compliance in dogs

BackgroundGastric electrical stimulation (GES) with short pulses improves nausea and vomiting in patients with gastroparesis, whereas GES with long pulses improves gastric motility.AimsTo assess the effects of a novel method of GES using dual pulse (both short and long pulses) on gastric tone, compliance and sympathovagal activity in dogs.Materials and methodsThe study was performed in 7 dogs implanted with a gastric cannula and a pair of gastric serosal electrodes for dual pulse GES. The study was composed of a number of sessions on different days with different stimulation parameters, including variations in the number of short pulses and stimulation amplitude.Results(1) Dual pulse GES of one short pulse and one long pulse with various amplitudes inhibited gastric tone (p < 0.05) but did not alter sympathetic or vagal activity. (2) Dual pulse GES with five short pulses and one long pulse not only inhibited gastric tone, but also reduced sympathetic activity and increased vagal activity (p < 0.05). (3) Dual pulse GES with five short pulses and one long pulse significantly increased gastric compliance.ConclusionsDual pulse GES reduces gastric tone and increases gastric compliance. The variation in the number of short pulse affects the sympathetic and vagal activities, whereas, the increase in stimulation strength enhances its effects on gastric tone.     

Reverse gastric pacing reduces food intake without inducing symptoms in dogs

OBJECTIVE:To investigate the therapeutic potential of reverse gastric pacing (RGP) for obesity by studying the effects of RGP on food intake and symptoms in dogs. MATERIAL AND METHODS: The study was performed in 9 dogs in 3 sessions (control, strong RGP and moderate RGP). Gastric myoelectrical activity and food intake were measured in each session. RGP was performed using serosal electrodes implanted in the distal stomach at the physiological frequency of the intrinsic gastric myoelectrical activity with a pulse width of 550-950 ms. The amplitude of the stimulus was set at a level maximally tolerable by the animals in the strong RGP session and 50% of the maximum level in the moderate session. RESULTS: 1) Compared with the control, strong RGP (p<0.001) and moderate RGP (p<0.01) significantly reduced the amount of food intake by 62.9% and 31.7%, respectively (p<0.05, ANOVA). 2) Whereas strong RGP induced significant symptoms, moderate RGP did not induce any significant symptoms in comparison with the control session. 3) The regularity and coupling of gastric myoelectrical activity were significantly impaired with both strong RGP and moderate RGP in the fasting state. CONCLUSIONS: RGP impairs intrinsic gastric myoelectrical activity and substantially and acutely reduces food intake. The reduced food intake and freedom from symptoms resulting from moderate RGP are indicative of the therapeutic potential of RGP in obesity.     

Reverse gastric pacing reduces food intake without inducing symptoms in dogs

Objective. To investigate the therapeutic potential of reverse gastric pacing (RGP) for obesity by studying the effects of RGP on food intake and symptoms in dogs. Material and methods. The study was performed in 9 dogs in 3 sessions (control, strong RGP and moderate RGP). Gastric myoelectrical activity and food intake were measured in each session. RGP was performed using serosal electrodes implanted in the distal stomach at the physiological frequency of the intrinsic gastric myoelectrical activity with a pulse width of 550–950 ms. The amplitude of the stimulus was set at a level maximally tolerable by the animals in the strong RGP session and 50% of the maximum level in the moderate session. Results. 1) Compared with the control, strong RGP (p<0.001) and moderate RGP (p<0.01) significantly reduced the amount of food intake by 62.9% and 31.7%, respectively (p<0.05, ANOVA). 2) Whereas strong RGP induced significant symptoms, moderate RGP did not induce any significant symptoms in comparison with the control session. 3) The regularity and coupling of gastric myoelectrical activity were significantly impaired with both strong RGP and moderate RGP in the fasting state. Conclusions. RGP impairs intrinsic gastric myoelectrical activity and substantially and acutely reduces food intake. The reduced food intake and freedom from symptoms resulting from moderate RGP are indicative of the therapeutic potential of RGP in obesity.     

Long-pulse gastric electrical stimulation protects interstitial cells of Cajal in diabetic rats via IGF-1 signaling pathway

AIM: To investigate the effects of different parameters of gastric electrical stimulation(GES) on interstitial cells of Cajal(ICCs) and changes in the insulin-like growth factor 1(IGF-1) signal pathway in streptozotocininduced diabetic rats.METHODS: Male rats were randomized into control, diabetic(DM), diabetic with sham GES(DM + SGES), diabetic with GES1(5.5 cpm, 100 ms, 4 m A)(DM + GES1), diabetic with GES2(5.5 cpm, 300 ms, 4 m A)(DM + GES2) and diabetic with GES3(5.5 cpm, 550 ms, 2 m A)(DM + GES3) groups. The expression levels of c-kit, M-SCF and IGF-1 receptors were evaluated in the gastric antrum using Western blot analysis. The distribution of ICCs was observed using immunolabeling for c-kit, while smooth muscle cells and IGF-1 receptors were identified using α-SMA and IGF-1R antibodies. Serum level of IGF-1 was tested using enzyme-linked immunosorbent assay. RESULTS: Gastric emptying was delayed in the DM group but improved in all GES groups, especially in the GES2 group. The expression levels of c-kit, M-SCF and IGF-1R were decreased in the DM group but increased in all GES groups. More ICCs(c-kit+) and smooth muscle cells(α-SMA+/IGF-1R+) were observed in all GES groups than in the DM group. The average level of IGF-1 in the DM group was markedly decreased, but it was up-regulated in all GES groups, especially in the GES2 group. CONCLUSION: The results suggest that long-pulse GES promotes the regeneration of ICCs. The IGF-1 signaling pathway might be involved in the mechanism underlying this process, which results in improved gastric emptying.     

Gastric or intestinal electrical stimulation-induced increase in gastric volume is correlated with reduced food intake

OBJECTIVE: Satiation has recently been shown to be associated with gastric volume or gastric tone. Electrical stimulation has been shown to reduce food intake and increase gastric volume, or reduce gastric tone. The aim of this study was to investigate the correlation between gastric or intestinal electrical stimulation (GES/IES)-induced increase in gastric volume and food intake. MATERIAL AND METHODS: GES/IES was performed on 14 dogs implanted with electrodes and a gastric cannula. Food intake was measured and gastric volume was assessed using barostat with or without GES/IES. RESULTS: Food intake was correlated to weight (r = 0.62, p = 0.02) as well as the fasting gastric volume (r = 0.59, p = 0.02). GES/IES reduced food intake (240.8 versus 445.0 g, p < 0.005) and increased gastric volume in the fasting state (263.4 versus 74.4 ml, p < 0.0001). Reduced food intake was correlated to the preprandial gastric volume (r = - 0.58, p = 0.02) and postprandial increase in gastric volume with GES/IES (r = 0.56, p = 0.03). CONCLUSIONS. GES/IES reduces food intake and increases gastric volume measured by barostat. The GES/IES-induced increase in gastric volume (or reduced gastric tone) is correlated with reduced food intake during GES/IES.     

Is rectosigmoid response to food modulated by proximal colon stimulation?

Rectosigmoid motor activity and postprandial breath hydrogen levels were monitored in eight healthy males under basal conditions and for 3 1/2 hr after a meal (beefburger and breadroll and ice cream incorporating 20 g lactulose). Within minutes of ingestion there was a significant increase in motility index (P<0.05) and also an initial temporary rise in breath hydrogen. A late increase in motor activity occurred in seven of eight subjects 123 ±19 min after the meal and was temporally related to the beginning of a second, much larger rise in breath hydrogen (r=0.99;P<0.01). The close association between the timing of the rises in breath hydrogen and rectosigmoid motor activity would support the possibility that the latter may be generated by chemical or mechanical stimulation of the proximal colon.     

Urocortin reduces food intake and gastric emptying in lean and ob/ob obese mice.

BACKGROUND & AIMS: Gastric emptying plays an important role in regulating food intake. This study was designed to investigate whether intraperitoneally injected urocortin reduces gastric emptying, feeding, and body weight in lean and ob/ob obese mice. METHODS: Food intake and body weight were measured after intraperitoneal injections of one of the following: urocortin, deamidated form of urocortin (urocortin OH), corticotropin-releasing factor (CRF), CRF6-33, cholecystokinin octapeptide (CCK-8), and leptin in 16-hour food-deprived animals. Gastric emptying was assessed 2, 4, or 8 hours after intraperitoneal injection. Repeated injections of urocortin were continued for 5 days in ob/ob mice. RESULTS: Urocortin (0.003-3 nmol) dose-dependently and potently decreased food intake and body weight gain in lean mice. The ranking order of potency was urocortin > urocortin OH >/= CRF > CCK-8 > CRF6-33 > leptin. Gastric emptying was also potently reduced by urocortin with a similar ranking order of potency of urocortin > CRF > urocortin OH > CCK-8. Simultaneous administration of urocortin and CRF receptor antagonist, alpha-helical CRF9-41, blocked the effects of urocortin. Urocortin reduced food intake and body weight gain, as well as the rate of gastric emptying, in ob/ob mice, which was significantly faster than that of lean mice. Five daily injections of urocortin significantly lowered body weight and improved glycemic control in ob/ob mice. CONCLUSIONS: The urocortin-induced decrease in food intake and body weight in lean and ob/ob mice is closely related to gastric emptying and opens new possibilities for the treatment of obesity.     

Microchip vagal pacing reduces food intake and body mass

BACKGROUND/AIMS: Morbid obesity is an increasing problem worldwide. In many patients pharmacotherapy is ineffective and these cases are treated by surgery. Different types of gastroplasty and gastric bypasses have been described. However, all of these ablative surgical methods are irreversible and often replace obesity by other disorders. Neuromodulation of vagal activity is a method of inducing significant changes in stomach motility. We developed a pre-programmed microchip able to pace vagal afferent activity by changing current parameters. The aim of our study was to evaluate long-term effects of vagal neuromodulation on food intake and body mass in rabbits. METHODOLOGY: Twenty-seven healthy male adult New Zealand white rabbits were included into the study and divided into three groups: A, B and C, 9 animals each. Microchips were implanted by laparotomy access. Anesthesia was obtained by continuous intravenous infusion of propofol. Microchips were fixed in the preperitoneal pocket and two electrodes were positioned on the posterior vagus in group A by forward, and in group B by backward pacing. Control group C was sham operated by laparotomy and only vagal nerves preparation was performed. The following parameters were estimated: daily solid food and liquids intake, amount of feces, body mass and heart rate. RESULTS: Within four weeks after operation body mass in group B had decreased up to 12% (P = 0.029), whereas in group A and C changed to -3% and +2%, respectively. An 87% solid food intake was observed in group A, 60% in group B (P < 0.01), and 143% in group C, compared to preoperative period. No significant differences were observed between groups A, B and C for liquids intake. Total feces weight changes corresponded to solid food intake. Heart rate decreased intraoperatively to 78% and 74% in groups A and B, respectively. CONCLUSIONS: Microchip mediated functional gastroplasty significantly reduces food intake and body mass. Obtained results encourage using similar treatment in morbid obesity human patients. However, further studies are required.     

Oxyntomodulin suppresses appetite and reduces food intake in humans

Oxyntomodulin (OXM) is released from the gut postprandially, in proportion to energy intake, and circulating levels of OXM are elevated in several conditions associated with anorexia. Central injection of OXM reduces food intake and weight gain in rodents, suggesting that OXM signals food ingestion to hypothalamic appetite-regulating circuits. We investigated the effect of iv OXM (3.0 pmol/kg.min) on appetite and food intake in 13 healthy subjects (body mass index, 22.5 +/- 0.9 kg/m(2)) in a randomized, double-blind, placebo-controlled, cross-over study. Infusion of OXM significantly reduced ad libitum energy intake at a buffet meal (mean decrease, 19.3 +/- 5.6%; P < 0.01) and caused a significant reduction in scores for hunger. In addition, cumulative 12-h energy intake was significantly reduced by infusion of OXM (mean decrease, 11.3 +/- 6.2%; P < 0.05). OXM did not cause nausea or affect food palatability. Preprandial levels of the appetite-stimulatory hormone, ghrelin, were significantly suppressed by OXM (mean reduction, 44 +/- 10% of postprandial decrease; P < 0.0001). Elevated levels of endogenous OXM associated with disorders of the gastrointestinal tract may contribute to anorexia.     

Feasibility of gastric electrical stimulation by use of endoscopically placed electrodes

BACKGROUND: Gastric electrical stimulation (GES), which has been reported to have therapeutic potentials for gastroparesis and obesity, involves the surgical placement of electrodes with the patient under general anesthesia. New methods are needed for implanting GES electrodes in a safer and more feasible way. OBJECTIVE: Our purpose was to investigate the safety and feasibility of placing electrodes endoscopically for GES. DESIGN AND SETTING: A pilot study. SUBJECTS: Six female hound dogs that weighed 13 to 22 kg. INTERVENTIONS: Endoscopically placed electrodes passed through the abdomen and the stomach wall. MAIN OUTCOME MEASUREMENTS: The study was performed in dogs surgically implanted with gastric serosal electrodes and endoscopically implanted electrodes. The experiment consisted of a 30-minute baseline, a 30-minute GES, and a 30-minute recovery. GES was performed through endoscopically placed electrodes. Gastric slow waves were simultaneously recorded with the serosal electrodes and the endoscopically placed electrodes. RESULTS: (1) The slow wave frequency recorded from the endoscopically placed electrodes was significantly correlated with that from the serosal electrodes (r = 0.97, P < .002). (2) GES through the endoscopically placed electrodes was able to entrain gastric slow waves. (3) No gastric leakage into the abdominal cavity was noted and the dogs were healthy and comfortable. (4) The endoscopically placed electrodes remained for 2 to 3 weeks. LIMITATIONS: The fixation of the electrodes needs to be improved for longer-term uses. CONCLUSIONS: GES may be accomplished without surgery by inserting the electrode wire through the abdomen under endoscopy. The study results indicate that the endoscopically placed electrodes are effective for GES and do not result in any adverse events.     

Therapeutic potential of duodenal electrical stimulation for obesity: acute effects on gastric emptying and water intake

OBJECTIVES: No satisfactory treatment is available for obesity. Previous animal studies suggested the therapeutic potential of intestinal electrical stimulation for obesity. The aim of this study was to investigate the effects of duodenal electrical stimulation (DES) on gastric emptying and water intake in healthy humans. METHODS: The study was performed in 12 healthy volunteers intubated with a feeding tube in the duodenum under endoscopy. There were three ring electrodes at the end tip of the tube and the two distal electrodes were used for recording and electrical stimulation. On two separate days, each subject underwent a session of DES with various stimulation parameters, a water-intake test with DES or with sham-DES, and a gastric-emptying test with DES or with sham-DES. RESULTS: DES did not induce any noticeable dyspeptic symptoms. The amount of water drunk by the subjects was significantly reduced from 897 +/- 88 ml with sham-DES to 673 +/- 63 ml with DES (p < 0.002). The mean T(50) of gastric emptying was significantly increased from 113.1 +/- 10.0 min with sham-DES to 176.5 +/- 20.8 min with DES state (p < 0.005). The gastric retention at 2 h was increased with DES (42.8 +/- 4.5% vs 61.4 +/- 4.7%; p < 0.02). CONCLUSIONS: DES delays gastric emptying and reduces water intake. It may have a potential application for the treatment of obesity.