Motility Of Antrum Research Articles

Safety and feasibility of early drinking water after general anesthesia recovery in patients undergoing daytime surgery

BackgroundPatients who are recovering from general anesthesia commonly exhibit symptoms such as dry lips, throat irritation, and thirst, prompting a desire to drink water in the post-anesthesia care unit (PACU). In this study, we aimed to evaluate the therapeutic effects and any potential complications of administering varying quantities of water to such patients. The primary objectives are to assess the safety and feasibility of early water intake after general anesthesia, specifically in the context of daytime surgery.MethodsA total of 200 nongastrointestinal patients who underwent outpatient surgery were randomly assigned to four groups: Group A (drinking < 1 ml/kg), Group B (drinking 1–2 ml/kg), Group C (drinking > 2 ml/kg), and Group D (no water intake). We monitored changes in the assessment parameters before and after water consumption, as well as the incidence of post-drinking nausea and vomiting, and compared these outcomes among the four groups.ResultsWater intake led to a significant reduction in thirst, oropharyngeal discomfort, and pain scores and a notable increase in the gastric antrum motility index (MI), exhibiting statistical significance compared to the values before drinking (p < 0.05). Remarkably, higher water consumption correlated with enhanced gastrointestinal peristalsis. There was a significant difference in the antral MI among groups B, C, and A (p < 0.05). The occurrence of nausea and vomiting did not significantly differ among groups A, B, C, and D (p > 0.05). Early water consumption enhanced patient satisfaction with medical care, significantly varying from Group D (p < 0.05).ConclusionNon-gastrointestinal surgical patients who passed pre-drinking water assessments post GA(general anesthesia)recovery could safely ingest moderate amounts of water in the PACU. Early water intake is both safe and feasible, effectively fostering swift postoperative recovery.

Mfge8 is expressed by pericytes in gastric antrum submucosa from patients with obesity.

The main function of the stomach is to digest ingested food. Gastric antrum muscular contractions mix ingested food with digestive enzymes and stomach acid and propel the chyme through the pyloric sphincter at a rate in which the small intestine can process the chyme for optimal nutrient absorption. Mfge8 binding to α8β1 integrins helps regulate gastric emptying by reducing the force of antral smooth muscle contractions. The source of Mfge8 within gastric muscles is unclear. Since Mfge8 is a secreted protein, Mfge8 could be delivered via the circulation, or be locally secreted by cells within the muscle layers. In this study, we identify a source of Mfge8 within human gastric antrum muscles using spatial transcriptomic analysis. We show that Mfge8 is expressed in subpopulations of Mef2c+ perivascular cells within the submucosa layer of the gastric antrum. Mef2c is expressed in subpopulations of NG2+ and PDGFRB+ pericytes. Mfge8 is expressed in NG2+/Mef2c+ pericytes, but not in NG2+/Mef2c-, PDGFRB+/Mef2c-, or PDGFRB+/Mef2c+ pericytes. Mfge8 is absent from CD34+ endothelial cells but is expressed in a small population of perivascular ACTA2+ cells. We also show that α8 integrin is not expressed by interstitial cells of Cajal (ICC), supporting the findings that Mfge8 attenuates gastric antrum smooth muscle contractions by binding to α8β1 integrins on enteric smooth muscle cells. These findings suggest a novel, supplementary mechanism of regulation of gastric antrum motility by cellular regulators of capillary blood flow, in addition to the regulation of gastric antrum motility by the enteric nervous system and the SMC, ICC, and PDGFRα+ cell (SIP) syncytium.

Short- and Long-Term Effects of Cocaine on Enteric Neuronal Functions.

Cocaine is one of the most consumed illegal drugs among (young) adults in the European Union and it exerts various acute and chronic negative effects on psychical and physical health. The central mechanism through which cocaine initially leads to improved performance, followed by addictive behavior, has already been intensively studied and includes effects on the homeostasis of the neurotransmitters dopamine, partly mediated via nicotinic acetylcholine receptors, and serotonin. However, effects on the peripheral nervous system, including the enteric nervous system, are much less understood, though a correlation between cocaine consumption and gastrointestinal symptoms has been reported. The aim of the present study was to gain more information on the effects of cocaine on enteric neuronal functions and the underlying mechanisms. For this purpose, functional experiments using an organ bath, Ussing chamber and neuroimaging techniques were conducted on gastrointestinal tissues from guinea pigs. Key results obtained are that cocaine (1) exhibits a stimulating, non-neuronal effect on gastric antrum motility, (2) acutely (but not chronically) diminishes responses of primary cultured enteric neurons to nicotinic and serotonergic stimulation and (3) reversibly attenuates neuronal-mediated intestinal mucosal secretion. It can be concluded that cocaine, among its central effects, also alters enteric neuronal functions, providing potential explanations for the coexistence of cocaine abuse and gastrointestinal complaints.

Xiangbinfang granules enhance gastric antrum motility via intramuscular interstitial cells of Cajal in mice.

BACKGROUNDInterdigestive migrating motor complexes (MMC) produce periodic contractions in the gastrointestinal tract, but the exact mechanism of action still remains unclear. Intramuscular interstitial cells of Cajal (ICC-IM) participate in gastrointestinal hormone and neuromodulation, but the correlation between ICC-IM and MMC is also unclear. We found that xiangbinfang granules (XBF) mediated the phase III contraction of MMC. Here, the effects of XBF on gastric antrum motility in W/Wv mice and the effects of ICC-IM on gastric antrum MMC are reported.AIMTo observe the effects of ICC-IM on gastric antrum motility and to establish the mechanism of XBF in promoting gastric antrum motility.METHODSThe density of c-kit-positive ICC myenteric plexus (ICC-MP) and ICC-IM in the antral muscularis of W/Wv and wild-type (WT) mice was examined by confocal microscopy. The effects of XBF on gastric antrum slow waves in W/Wv and WT mice were recorded by intracellular amplification recording. Micro-strain-gauge force transducers were implanted into the gastric antrum to monitor the MMC and the effect of XBF on gastric antrum motility in conscious W/Wv and WT mice.RESULTSIn the gastric antrum of W/Wv mice, c-kit immunoreactivity was significantly reduced, and no ICC-IM network was observed. Spontaneous rhythmic slow waves also appeared in the antrum of W/Wv mice, but the amplitude of the antrum slow wave decreased significantly in W/Wv mice (22.62 ± 2.23 mV vs 2.92 ± 0.52 mV, P < 0.0001). MMCs were found in 7 of the 8 WT mice but no complete MMC cycle was found in W/Wv mice. The contractile frequency and amplitude index of the gastric antrum were significantly increased in conscious WT compared to W/Wv mice (frequency, 3.53 ± 0.18 cpm vs 1.28 ± 0.12 cpm; amplitude index, 23014.26 ± 1798.65 mV·20 min vs 3782.16 ± 407.13 mV·20 min; P < 0.0001). XBF depolarized smooth muscle cells of the gastric antrum in WT and W/Wv mice in a dose-dependent manner. Similarly, the gastric antrum motility in WT mice was significantly increased after treatment with XBF 5 mg (P < 0.05). Atropine (0.1 mg/kg) blocked the enhancement of XBF in WT and W/Wv mice completely, while tetrodotoxin (0.05 mg/kg) partially inhibited the enhancement by XBF.CONCLUSIONICC-IM participates in the regulation of gastric antrum MMC in mice. XBF induces MMC III-like contractions that enhance gastric antrum motility via ICC-IM in mice.

Hypothalamo‐Vagal Oxytocinergic Neurocircuits Modulate Gastric Emptying And Motility Following Stress

Stress triggers and exacerbates the symptoms of functional gastrointestinal (GI) disorders, such as delayed gastric emptying and impaired gastric motility. The prototypical anti‐stress hormone, oxytocin (OXT), modulates GI tone and motility via vagal pathways. Following acute or chronic stress, the oxytocinergic neurocircuits from the hypothalamus to brainstem neurons of the dorsal vagal complex (DVC) undergo neuroplasticity. However, the physiological role of this neuroplasticity in modulating gastric functions following stress is yet unclear. In this study, we used chemogenetic technology to test the hypothesis that activation of hypothalamo‐vagal oxytocinergic neurocircuits plays a pivotal role in the modulation of gastric emptying and motility following stress.Male Sprague‐Dawley rats were used in all experiments. Six‐week‐old rats received bilaterally microinjections of AAV‐OXT‐Cre in the paraventricular nucleus of the hypothalamus (PVN), and retrogradely transported AAV that express Cre‐inducible hM3Dq (hM3Dq rats), hM4Di (hM4Di rats) or EGFP (EGFP rats, i.e. viral control) in the DVC. Four weeks after AAV injections, gastric emptying (GE) was assessed via the non‐invasive [13C]‐octanoic acid breath test technique. After 3 days of daily acclimation to the test chamber, two baseline of GE were taken 5 days apart. GE was then measured immediately following acute stress and after 5 days of either chronic homotypic (CHo, rats showed adaptation to stress) or heterotypic stress (CHe, rats did not adapt to stress). Our data showed that the baseline GE t1/2 was not different among hM3Dq, hM4Di and EGFP rats (70±3.5, 75±2.3, and 70±2.5 min, respectively; N=12–24, p&gt;0.05, one‐way ANOVA). Acute stress (2hr restraint) delayed GE significantly in both EGFP and hM4Di rats that received either saline or CNO treatment. Delayed GE was also observed in hM3Dq rats that received saline; however, CNO administration to hM3Dq rats prevented the delay in GE. Following CHe, EGFP rats that received saline or CNO still showed delayed GE, whereas CNO administration to hM3Dq rats restored the delayed GE. Following CHo, GE of EGFP rats was restored to baseline, whereas CNO administration to hM4Di rats delayed GE.Another group of rats were anesthetized to monitor gastric motility via strain gauges sewn on the gastric wall. Application of CNO (20nmoles) on the floor of 4th ventricle of EGFP rats changed neither tone nor motility (−2.5±2 mg and 104±8% vs baseline, respectively). Conversely, CNO increased corpus tone (68±33mg) and antrum motility (158±21% vs baseline) when applied to hM3Dq rats following CHe, but decreased tone (−63±17mg) and motility (85±21% vs. baseline) when applied to hM4Di rats following CHo. Pretreatment of OXT receptor antagonist, atosiban, abolished the effects of CNO. Taken together, our data support the hypothesis that hypothalamo‐vagal oxytocinergic neurocircuits modulate gastric emptying and motility following stress.Support or Funding InformationNIDDK 120170 and TSF CURE funds GE (vs baseline) Acute stress CHe CHo Saline CNO Saline CNO Saline CNO EGFP (Control) 138±8% * (N=9) 135±13% * (N=12) 139±15% * (N=4) 134±16% * (N=6) 100±8% (N=4) 107±5% (N=6) hM3Dq 151±9% * (N=5) 81±12% (N=5) 134±13% * (N=5) 90±13% (N=5) hM4Di 118±7% * (N=6) 133±14% * (N=4) 119±7% (N=6) 141±9% * (N=4) *P&lt;0.05, paired Student’s t‐test vs own baseline

Clinical efficacy of Huxiang-Yangwei powder combined with conventional western medicine on gastric motility and gastrointestinal hormones in patients with chronic atrophic gastritis

Objective To observe clinical effect of Huxiang-Yangwei powder combined with conventional western medicine on gastric motility and gastrointestinal hormones in patients with chronic atrophic gastritis. Methods A total of 100 patients with chronic atrophic gastritis according to the inclusion criteria were randomly divided into the observation group and the control group, with 50 cases in each group. The control group was given routine symptomatic treatment. Based on the treatment of control group, the observation group was given Huxiang-Yangwei powder therapy. After 1 month, the gastroscope score, pathological tissue score, gastric motility index (gastric motility rhythm, gastroelectric rhythm and gastric antrum motility), and the improvement of plasma gastrointestinal hormone (MTL, GAS, SS) were compared. Results The total effective rate of the observation group was 92.0% (42/50), and the total effective rate of the control group was 78.0% (39/50), with statistically significant (Z=-2.978, P=0.003). After treatment, the under gastroscope score (0.59 ± 0.06 vs. 1.23 ± 0.17, t=4.877) and the pathological organization score (0.65 ± 0.08 vs. 1.33 ± 0.19, t=5.096) of the observation group were significantly lower than those of the control group (P<0.05). After treatment, the gastric motility rhythm (76.15% ± 8.77% vs. 62.35% ± 7.31%, t=5.301), gastroelectric rhythm (81.02% ± 9.23% vs. 73.02% ± 8.43%, t=5.286), gastric antral motility (0.012 ± 0.002 Ω vs. 0.008 ± 0.001 Ω, t=4.160) of the observation group were significantly higher than those of the control group (P<0.05). After treatment, the plasma MTL (246.73 ± 31.82 pg/ml vs. 203.86 ± 27.91 pg/ml, t=5.832), GAS (49.55 ± 6.25 pg/ml vs. 35.81 ± 4.63 pg/ml, t=5.126), SS (17.35 ± 2.76 pg/ml vs. 15.01 ± 2.60 pg/ml, t=4.970) of the observation group were significantly higher than those of the control group (P<0.05). Conclusions The application of Huxiang-Yangwei powder in the treatment of chronic atrophic gastritis patients can repair gastric mucosa, regulate gastrointestinal hormone levels and increase gastric motility. Key words: Gastritis, atrophic; Huxiang-Yangwei powder; Gastric emptying; Prokinetic drugs (TCD); Motilin; Plastering therapy

Sex Differences And Stress Alter The Vagally‐Mediated Gastric Response To Oxytocin In Rats

Stress and stress maladaptation play critical roles in the development of functional gastrointestinal (GI) disorders. Females have a higher incidence of functional GI disorders, likely due to fluctuations in estrogen levels, which we have shown to correlate with increased inhibitory vagal output to the GI tract. Previous studies have shown that levels of anti‐stress hormone oxytocin vary in response to stress: the more oxytocin the better the individual copes with stressful events. Furthermore, our previous studies (PMC4287746) showed that acute stress induces plastic changes in the vagally‐mediated gastric response to oxytocin, however gastric motility responses to brainstem application of oxytocin in male vs female in response to chronic stress are not yet known.The aim of this study was to test the hypothesis that sex differences and stress alter the gastric, vagally‐mediated response to oxytocin.SD rats were divided into the following groups 1) male, 2) low estrogen female, and 3) high estrogen female. Rats were further subdivided into the following groups: i) control, and 5 consecutive days of ii) chronic repetitive homotypic stress (these rats adapt to stress; CHo), and iii) chronic repetitive heterotypic stress (these rats do not adapt to stress; CHe). At the end of the stress load, rats were anaesthetized and strain gauges were sewn to the anterior stomach to record antrum and corpus tone and motility variation upon oxytocin microinjected in the dorsal motor nucleus of the vagus to record the changes in corpus and antrum. The postganglionic vagal pathway affected by oxytocin was investigated via i.v. injection of L‐NAME, VIP antagonist or bethanechol.Focusing on antrum motility, but similar data were obtained with corpus tone and motility as well as antrum tone, our results suggest: i) in male rats (N=4 for all) the oxytocin induced inhibition in antral motility was attenuated significantly by L‐NAME only in controls (from 65±5% to 23±7% decrease from baseline), while in stressed animals, the response was mediated also via engagement of a VIP‐dependent pathway. ii) in all the groups from low or high estrogen females (N=3 for all), the oxytocin‐mediated gastric response was regulated via both L‐NAME (from 53±5% to 43±7% decrease from baseline, in high estrogen control) and VIP‐sensitive pathways (from 53±5 to 8±36% decrease from baseline, in high estrogen control).In conclusion, our data indicate that females appear to respond to oxytocin to a lesser extent than males, and the vagally‐mediated pathways controlling tone and motility by females are similar to those used by stressed males. These observations may lead to a better explanation of the higher incidence of functional GI disorders in females.Support or Funding InformationAmerican Physiological Society, Undergraduate Summer Research FellowshipThis abstract is from the Experimental Biology 2018 Meeting. There is no full text article associated with this abstract published in The FASEB Journal.

Gut Motility Alterations in Neonates and Young Infants

C olic usually affects babies in the first few weeks of their lives and persists for about 4 months. Crying can be intense and furious and it may last for several hours per day for several weeks. Although crying can occur at any time, it is usually worse in the late afternoon and evening, and occasionally affects the baby’s sleep. Infantile colic is not considered a disease, fulfilling instead criteria for a functional disorder. Research shows that babies with colic continue to eat and gain weight appropriately, despite the crying (1). The main risk for these babies relates to the stress and anxiety that the condition creates at home, especially when it affects the first child. The cause of colic is not known. Painful flatus may contribute to colic, but there is little evidence to prove that it is linked to digestive problems (2). Another theory is that while the digestive system is maturing, some babies are more sensitive to substances such as lactose ingested through breast-feeding and formula milk; however, evidence to support this hypothesis also is limited. Other possible causes relate to the baby’s behavior and temperament. Among the gastrointestinal (GI) factors, we focus on non-nutritive pathophysiology such as the relation of colic to gastroesophageal reflux (GER), GI motility disorders, the role of gut hormones, and intestinal microflora.

Intragastric infusion of rikkunshito (kampo) induces proximal stomach relaxation in conscious dogs

Abnormal proximal gastric relaxation is one of the causes of functional dyspepsia. The purpose of this study is to use a barostat in conscious dogs to determine the effects of rikkunshito, which is considered to have beneficial effects on functional dyspepsia, on the proximal stomach. Eight beagles were used. A gastrocutaneous fistula and force transducers were surgically implanted in the middle corpus and gastric antrum and duodenum, respectively. After a recovery period, a plastic bag was inserted through the gastrocutaneous fistula and the proximal stomach was distended using a barostat. First, four dogs were used to investigate the pressure-volume relation in the fasted and postprandial phases. Second, the stomachs of four different dogs were continuously distended at minimal distending pressure +2 mmHg, and 5 min later were infused with warmed liquid rikkunshito (2 g/20 mL) or water through the gastrocutaneous fistula. Finally, changes in the proximal gastric volume and gastrointestinal motility were observed. The proximal stomach was significantly more pliable in the postprandial phase than in the fasted phase. The proximal gastric volume increased immediately after liquid infusion under constant pressure in both phases and duodenal motility was accelerated. The effect of rikkunshito was significantly greater and lasted longer than that of water. No significant difference between the effects during the fasted or postprandial phase and no change in the gastric antrum motility were observed when rikkunshito was infused. These results indicate that rikkunshito accelerates duodenal motility and relaxes the proximal stomach.

“Intensity-Response” Effects of Electroacupuncture on Gastric Motility and Its Underlying Peripheral Neural Mechanism

The aim of this study was to explore the “intensity-response” relationship between EAS and the effect of gastric motility of rats and its underlying peripheral neural mechanism by employing ASIC3 knockout (ASIC3−/−), TRPV1 knockout (TRPV1−/−), and C57BL/6 mice. For adult male Sprague-Dawley (n = 18) rats, the intensities of EAS were 0.5, 1, 3, 5, 7, and 9 mA, respectively. For mice (n = 8 in each group), only 1 mA was used, by which C fiber of the mice can be activated. Gastric antrum motility was measured by intrapyloric balloon. Gastric motility was facilitated by EAS at ST36 and inhibited by EAS at CV12. The half maximal facilitation intensity of EAS at ST36 was 2.1–2.3 mA, and the half maximal inhibitory intensity of EAS at CV12 was 2.8 mA. In comparison with C57BL/6 mice, the facilitatory effect of ST36 and inhibitive effect of CV12 in ASIC3−/− mice decreased, but the difference was not statistically significant (P > 0.05). However, these effects in TRPV1−/− mice decreased significantly (P < 0.001). The results indicated that there existed an “intensity-response” relationship between EAS and the effect of gastric motility. TRPV1 receptor was involved in the regulation of gastric motility of EAS.

Ghrelin, Des-Acyl Ghrelin, and Obestatin: Regulatory Roles on the Gastrointestinal Motility

Ghrelin, des-acyl ghrelin, and obestatin are derived from a common prohormone, preproghrelin by posttranslational processing, originating from endocrine cells in the stomach. To examine the regulatory roles of these peptides, we applied the manometric measurement of gastrointestinal motility in freely moving conscious rat or mouse model. Ghrelin exerts stimulatory effects on the motility of antrum and duodenum in both fed and fasted state of animals. Des-acyl ghrelin exerts inhibitory effects on the motility of antrum but not on the motility of duodenum in the fasted state of animals. Obestatin exerts inhibitory effects on the motility of antrum and duodenum in the fed state but not in the fasted state of animals. NPY Y2 and Y4 receptors in the brain may mediate the action of ghrelin, CRF type 2 receptor in the brain may mediate the action of des-acyl ghrelin, whereas CRF type 1 and type 2 receptors in the brain may mediate the action of obestatin. Vagal afferent pathways might be involved in the action of ghrelin, but not involved in the action of des-acyl ghrelin, whereas vagal afferent pathways might be partially involved in the action of obestatin.

Optimal locations and parameters of gastric electrical stimulation in altering ghrelin and oxytocin in the hypothalamus of rats

Gastric electric stimulation (GES) has been shown to decrease gastric tone and antrum motility, delay gastric empty, suppress appetite and induce weight loss in animal models. Our previous studies have shown that GES activates gastric-distension responsive neurons in several satiety related hypothalamic nuclei; Two hour acute GES at gastric antrum can alter the expression of anorexigenic and orexigenic peptides in the hypothalamus of rats. Aim To investigate the effects of GES with different stimulation parameters and locations on the neuronal expression of a hunger hormone, ghrelin and a satiety hormone, oxytocin (OT) in the hypothalamus of rats. Methods With immunohistochemical technique, changes in expression of satiety-related peptides-containing (OT- and ghrelin-) neurons with GES in the rodent hypothalamus were assessed. GES was performed for 2 h using six different sets of parameters at three different locations. Results (1) The number of ghrelin/OT-immunoreactive (IR) neurons was significantly decreased/increased with GES of the standard parameters (pulse trains: train on-time of 2 s, off-time of 3 s, pulse amplitude of 6 mA, width of 0.3 ms and frequency of 40 Hz) in both the paraventricular nucleus (PVN) and the superoptical nucleus (SON) compared with the control group, but not with GES of reduced pulse amplitudes, frequencies or train-on times. (2) GES with the standard parameters at the antrum resulted in a significant decrease/increase in the expression of ghrelin/OT in the PVN and the SON. However, GES at other locations (middle of lesser curvature or greater curvature) was not effective in altering the expression of ghrelin/OT. Conclusions GES with the standard parameters delivered at the distal antrum increases/decreases oxytocin/ghrelin in the hypothalamus of rats. GES with reduced parameters or delivered at the middle of the stomach is ineffective in altering these peptides.

Different effects of ghrelin, des-acyl ghrelin and obestatin on gastroduodenal motility in conscious rats

Three peptides, ghrelin, des-acyl ghrelin and obestatin are derived from a common prohormone, preproghrelin by posttranslational processing, originating from endocrine cells in the stomach. To examine the effects of these peptides, we applied the manometric measurement of gastrointestinal motility in freely moving conscious rat models. Ghrelin exerts stimulatory effects on the motility of antrum and duodenum in both fed and fasted state of animals. Des-acyl ghrelin exerts inhibitory effects on the motility of antrum, but not on the motility of duodenum in the fasted state of animals. Obestatin exerts inhibitory effects on the motility of antrum and duodenum in the fed state, but not in the fasted state of animals. NPY Y2 or Y4 receptors in the brain may mediate the action of ghrelin, CRF type 2 receptors in the brain mediate the action of des-acyl ghrelin, whereas CRF type 1 and type 2 receptors in the brain mediate the action of obestatin. Vagal afferent pathways might be involved in the action of ghrelin, but not involved in the action of des-acyl ghrelin, whereas vagal afferent pathways might be partially involved in the action of obestatin.

Stimulatory role of the dorsal motor nucleus of the vagus in gastrointestinal motility through myoelectromechanical coordination in cats

This study was undertaken to investigate the effect of stimulation of the dorsal motor nucleus of the vagus (DMV) on myoelectric activity and motility of the gastric antrum and duodenum in normal and in vagotomized cats. 37 cats were starved for 24 h and then anesthetized with a-chloralose (70–80 mg/kg, iv). Electrical stimulation (0.1 mA, 0.2 ms, 50 Hz) of the left DMV was performed through a stereotaxically inserted electrode in 19 of the cats. The remaining 18 cats were injected in the left DMV with a glutamate solution (1 M, 200 nl) through an inserted 3-barreled micropipette. The myoelectric activity (slow wave) and the motility of the gastric antrum (2 cm proximal to the pylorus) and duodenum (3 cm distal to the pylorus) were measured using serosal bipolar electrodes and intraluminal balloons. Both the electrical and the glutamate stimulations of the DMV markedly increased the occurrence of spike potentials on the antral and duodenal myoelectric activity; however, the stimulations significantly decreased the frequency of the antral slow wave. The stimulations also produced increases in the motility of the antrum and duodenum which corresponded to the changes in the myoelectric activity. All the changes in the myoelectric activity and the motility were not observed after the ipsilateral vagotomy. Thus, these results strongly suggest that the dorsal motor nucleus of the vagus has a stimulatory influence on antral and duodenal motility through myoelectromechanical coordination via the vagus nerve in cats.

Effects of KW-5338 (domperidone) on gastric motility.

The effects of KW-5338 (domperidone) on gastric motility were studied by the balloon method in pentobarbital anesthetized mongrel dogs. KW-5338 was found to enhance the antrum motility. Its enhancement pattern showed the following characteristics: (1) The tonus was not affected, (2) the contraction pressure increased, (3) the frequency of contraction decreased slightly, and (4) the enhancement was long lasting. Metoclopramide showed strong but short enhancement of antrum motility. KW-5338 augmented also the gastric body motility, although the enhancement pattern was different from that in the antrum: (1) The action did not last so long, and (2) an increase in tonus was observed. The augmentation of the gastric motility by KW-5338 was observed even after vagotomy and splanchnicotomy, but it was weaker and shorter than in the intact state. THe KW-5338 induced augmentation was diminished by tetrodotoxin treatment. The gastric relaxation response to dopamine was blocked by KW-5338. These results show that KW-5338 activates the gastric motility not only by central mechanism but also by stimulation to intramural neurons. The dopamine blocking activity of KW-5338 might play some role in the enhancement of gastric motility.

Antrum Motility as a Stimulus for Gastric Secretion

Summary Observations have been recorded concerning the effects of various procedures such as removal of vagus innervation, transplantation of the antrum to the abdominal wall and into the colon, on the total output of gastric juice from a Pavlov pouch. It is concluded that the hormonal or antrum phase of gastric secretion is most important, the nervous phase of secretion is somewhat less, and the intestinal phase is least important in provoking the secretion of gastric juice from a Pavlov accessory stomach pouch. The antrum of the stomach, transplanted into the colon, causes a greater secretion of gastric juice than is produced when the antrum is in its normal location. This secretion may continue even though the original blood supply to the antrum is divided, and it is nourished by newly formed blood vessels from the colon. In the absence of other factors, the development of pressure within the isolated colon containing an antrum transplant as a result of peristalsis is a profound stimulation for antrum function. The significance of this finding as a possible explanation for the increase in gastric secretion accompanying pyloric stenosis in man is suggested.