Modulation of gastric motor activity by a centrally acting stimulus, circular vection, in humans

2001 ◽  
Vol 280 (5) ◽  
pp. G850-G857 ◽  
Author(s):  
Henryk Faas ◽  
Christine Feinle ◽  
Paul Enck ◽  
David Grundy ◽  
Peter Boesiger
Keyword(s):  
Gastric Emptying ◽  
Healthy Subjects ◽  
Time Course ◽  
Delayed Gastric Emptying ◽  
Contractile Activity ◽  
Subjective Symptom ◽  
Gastric Volume ◽  
Rapid Decrease ◽  
Resonance Imaging ◽  
Baseline Activity

The aims of this study were to investigate gastric motor correlates of vection, a centrally acting stimulus, and relate these responses to the induction of motion sickness symptoms. Antral contractile activity and gastric volume retained after a liquid nutrient meal (600 ml) were assessed by magnetic resonance imaging in healthy subjects during two different protocols. Vection was induced by an optokinetic drum, and subjects repeatedly rated the intensity of vection and nausea on 0–10 analog scales. Vection delayed gastric emptying {99% (89–102%) [median (interquartile ranges)] of volume retained at 28 min; control situation: 79% (69–81%), P < 0.05}. Antral contractile activity followed a distinct time course of rapid decrease [−64% (−72 to −59%) change from baseline activity] immediately after onset of drum rotation followed by gradual recovery upon withdrawal of the stimulus. No relationship was found between the severity of nausea and inhibition of gastric emptying or antral contractile activity. The inhibition of antral contractile activity appears to be a good measure of the peripheral response to vection but is probably independent of subjective symptom induction.

Relative contributions of “pressure pump” and “peristaltic pump” to gastric emptying

2000 ◽  
Vol 278 (4) ◽  
pp. G604-G616 ◽  
Author(s):  
K. Indireshkumar ◽  
James G. Brasseur ◽  
Henryk Faas ◽  
Geoffrey S. Hebbard ◽  
Patrik Kunz ◽  
...  
Keyword(s):  
High Pressure ◽  
Gastric Emptying ◽  
Muscle Tone ◽  
Contractile Activity ◽  
Average Rate ◽  
Gastric Volume ◽  
Peristaltic Pump ◽  
Pressure Pump ◽  
Significant Difference ◽  
Common Cavity

The relative contributions to gastric emptying from common cavity antroduodenal pressure difference (“pressure pump”) vs. propagating high-pressure waves in the distal antrum (“peristaltic pump”) were analyzed in humans by high-resolution manometry concurrently with time-resolved three-dimensional magnetic resonance imaging during intraduodenal nutrient infusion at 2 kcal/min. Gastric volume, space-time pressure, and contraction wave histories in the antropyloroduodenal region were measured in seven healthy subjects. The subjects fell into two distinct groups with an order of magnitude difference in levels of antral pressure activity. However, there was no significant difference in average rate of gastric emptying between the two groups. Antral pressure history was separated into “propagating high-pressure events” (HPE), “nonpropagating HPEs,” and “quiescent periods.” Quiescent periods dominated, and average pressure during quiescent periods remained unchanged with decreasing gastric volume, suggesting that common cavity pressure levels were maintained by increasing wall muscle tone with decreasing volume. When propagating HPEs moved to within 2–3 cm of the pylorus, pyloric resistance was found statistically to increase with decreasing distance between peristaltic waves and the pylorus. We conclude that transpyloric flow tends to be blocked when antral contraction waves are within a “zone of influence” proximal to the pylorus, suggesting physiological coordination between pyloric and antral contractile activity. We further conclude that gastric emptying of nutrient liquids is primarily through the “pressure pump” mechanism controlled by pyloric opening during periods of relative quiescence in antral contractile wave activity.

Pressure-geometry relationship in the antroduodenal region in humans

2001 ◽  
Vol 281 (5) ◽  
pp. G1214-G1220 ◽  
Author(s):  
Henryk Faas ◽  
Geoffrey S. Hebbard ◽  
Christine Feinle ◽  
Patrik Kunz ◽  
James G. Brasseur ◽  
...  
Keyword(s):  
Gastric Emptying ◽  
Glucose Solution ◽  
Contractile Activity ◽  
Propagation Speed ◽  
Intragastric Administration ◽  
Control Mechanisms ◽  
Resonance Imaging ◽  
High Resolution Manometry ◽  
Gastric Motor Function ◽  
Nutrient Infusion

Understanding of the control mechanisms underlying gastric motor function is still limited. The aim of the present study was to evaluate antral pressure-geometry relationships during gastric emptying slowed by intraduodenal nutrient infusion and enhanced by erythromycin. In seven healthy subjects, antral contractile activity was assessed by combined dynamic magnetic resonance imaging and antroduodenal high-resolution manometry. After intragastric administration of a 20% glucose solution (750 ml), gastric motility and emptying were recorded during intraduodenal nutrient infusion alone and, subsequently, combined with intravenous erythromycin. Before erythromycin, contraction waves were antegrade (propagation speed: 2.7 ± 1.7 mm/s; lumen occlusion: 47 ± 14%). Eighty-two percent (51/62) of contraction waves were detected manometrically. Fifty-four percent of contractile events (254/473) were associated with a detectable pressure event. Pressure and the degree of lumen occlusion were only weakly correlated ( r 2 = 0.02; P = 0.026). After erythromycin, episodes of strong antroduodenal contractions were observed. In conclusion, antral contractions alone do not reliably predict gastric emptying. Erythromycin induces strong antroduodenal contractions not necessarily associated with fast emptying. Finally, manometry reliably detects ∼80% of contraction waves, but conclusions from manometry regarding actual contractile activity must be made with care.

Deep breath reversal and exponential return of methacholine-induced obstruction in asthmatic and nonasthmatic subjects

2004 ◽  
Vol 96 (1) ◽  
pp. 137-142 ◽  
Author(s):  
Andrew C. Jackson ◽  
Margaret M. Murphy ◽  
John Rassulo ◽  
Bartolome R. Celli ◽  
Roland H. Ingram
Keyword(s):  
Healthy Subjects ◽  
Time Course ◽  
Rapid Decrease ◽  
Airway Wall ◽  
Methacholine Challenge ◽  
Order Process ◽  
Deep Breath ◽  
First Order ◽  
Before And After ◽  
Complete Reversal

A deep breath (DB) during induced obstruction results in a transient reversal with a return to pre-DB levels in both asthmatic and nonasthmatic subjects. The time course of this transient recovery has been reported to be exponential by one group but linear by another group. In the present study, we estimated airway resistance (Raw) from measurements of respiratory system transfer impedance before and after a DB. Nine healthy subjects and nine asthmatic subjects were studied at their maximum response during a methacholine challenge. In all subjects, the DB resulted in a rapid decrease in Raw, which then returned to pre-DB levels. This recovery was well fit with a monoexponential function in both groups, and the time constant was significantly smaller in the asthmatic than the nonasthmatic subjects (11.6 ± 5.0 and 35.1 ± 15.9 s, respectively). Obstruction was completely reversed in the nonasthmatic subjects (pre- and postchallenge mean Raw immediately after the DB were 2.03 ± 0.66 and 2.06 ± 0.68 cmH2O·l-1·s, respectively), whereas in the asthmatic subjects complete reversal did not occur (2.29 ± 0.78 and 4.84 ± 2.64 cmH2O·l-1·s, respectively). Raw after the DB returned to postchallenge, pre-DB values in the nonasthmatic subjects (3.78 ± 1.56 and 3.97 ± 1.63 cmH2O·l-1·s, respectively), whereas in the asthmatic subjects it was higher but not significantly so (9.19 ± 4.95 and 7.14 ± 3.56 cmH2O·l-1·s, respectively). The monoexponential recovery suggests a first-order process such as airway wall-parenchymal tissue interdependence or renewed constriction of airway smooth muscle.

Influence of sildenafil on gastric sensorimotor function in humans

2004 ◽  
Vol 287 (5) ◽  
pp. G988-G992 ◽  
Author(s):  
Giovanni Sarnelli ◽  
Daniel Sifrim ◽  
Jozef Janssens ◽  
Jan Tack
Keyword(s):  
Gastric Emptying ◽  
Healthy Subjects ◽  
Soluble Guanylate Cyclase ◽  
Therapeutic Potential ◽  
Muscle Relaxation ◽  
Gastric Wall ◽  
Gastric Volume ◽  
Gastric Fundus ◽  
Smooth Muscle Relaxation ◽  
Gastric Accommodation

After a meal, the proximal stomach relaxes probably through the activation of nitrergic neurons in the gastric wall. Nitric oxide-induced smooth muscle relaxation involves activation of soluble guanylate cyclase, with cGMP production, which is then degradated by phosphodiesterase-5 (PDE-5). The aim of this study was to investigate the effect of sildenafil, a selective PDE-5 inhibitor, on fasting and postprandial proximal gastric volume and on gastric emptying rates in humans. A gastric barostat was used to study gastric compliance and perception to isobaric distension in healthy subjects before and after placebo ( n = 13) or sildenafil, 50 mg ( n = 15). In 10 healthy subjects, two gastric barostat studies were performed in randomized order to study the effect of placebo or sildenafil on postprandial gastric relaxation. Similarly, solid and liquid gastric emptying rates were studied in 12 healthy subjects. Sildenafil significantly increased fasting intragastric volume (141 ± 15 vs. 163 ± 15 ml, P < 0.05) and volumes of first perception. Sildenafil induced a higher and prolonged gastric relaxation either at 30 min (357 ± 38 vs. 253 ± 42 ml, P < 0.05) or 60 min (348 ± 49 vs. 247 ± 38 ml, P < 0.05) after the meal. Sildenafil did not alter solid half-emptying time but significantly delayed liquid emptying (43 ± 4 vs. 56 ± 4 min, P < 0.01). In conclusion, sildenafil significantly increases postprandial gastric volume and slows liquid emptying rate, confirming that meal-induced accommodation in humans involves the activation of a nitrergic pathway. The effect of sildenafil on gastric fundus suggests a therapeutic potential for phosphodiesterase inhibitors in patients with impaired gastric accommodation.

The effect of macronutrients on gastric volume responses and gastric emptying in humans: a magnetic resonance imaging study

2007 ◽  
Vol 292 (1) ◽  
pp. G11-G17 ◽  
Author(s):  
Oliver Goetze ◽  
Andreas Steingoetter ◽  
Dieter Menne ◽  
Ivo R. van der Voort ◽  
Monika A. Kwiatek ◽  
...  
Keyword(s):  
Magnetic Resonance Imaging ◽  
Gastric Emptying ◽  
Magnetic Resonance ◽  
Body Position ◽  
Gastrointestinal Symptoms ◽  
Imaging Study ◽  
Gastric Volume ◽  
Self Report ◽  
Mri Imaging ◽  
Resonance Imaging

The effects of macronutrients on gastric volume changes, emptying, and gastrointestinal symptoms are incompletely understood. Three liquid meals of 500 ml (fat emulsion, 375 kcal; protein solution, 375 kcal; glucose solution, 400 kcal) were infused into the stomach of 12 healthy volunteers on three occasions. Studies were performed in seated body position using an open-configuration magnetic resonance imaging (MRI) system. MRI imaging sequences, assessing stomach and meal volumes, were performed prior to and at times t = 0, 3, 6, 9, 12, 15, 25, 35, 45, 60, 75, and 90 min after meal administration. Areas under the curve for the early emptying phase (0–15 and 0–45 min) were calculated, and characteristics of the volume curves were analyzed by a gastric emptying model. Gastrointestinal symptoms were assessed by a self-report scale. Initial ( t = 0 min) and early postprandial gastric volumes were highest for glucose because of lower initial emptying. However, in the early emptying phase the characteristics of the volume curves for stomach and meal were uniform for all macronutrients. Perceptions of fullness and satiety were linearly associated with postprandial gastric volumes, but not with macronutrient composition. Isovolumic macronutrient meals modulate gastric volume response by initial meal emptying patterns. Macronutrient specific accommodation responses, as shown in barostat studies, are not reflected as gastric volume responses under noninvasive conditions.

Sa1431 Anorexia Nervosa Patients Have Dyspeptic Symptoms, Delayed Gastric Emptying and Reduced Gastric Contractile Activity

2012 ◽  
Vol 142 (5) ◽  
pp. S-304
Author(s):  
Sena Kuyumcu ◽  
Oliver Goetze ◽  
Peter Boesiger ◽  
Gabriella Milos ◽  
Michael Fried ◽  
...  
Keyword(s):  
Anorexia Nervosa ◽  
Gastric Emptying ◽  
Delayed Gastric Emptying ◽  
Contractile Activity ◽  
Dyspeptic Symptoms

Sumatriptan, a selective 5-HT1 receptor agonist, induces a lag phase for gastric emptying of liquids in humans

1997 ◽  
Vol 272 (4) ◽  
pp. G902-G908 ◽  
Author(s):  
B. Coulie ◽  
J. Tack ◽  
B. Maes ◽  
B. Geypens ◽  
M. De Roo ◽  
...  
Keyword(s):  
Gastric Emptying ◽  
Healthy Subjects ◽  
Receptor Agonist ◽  
Octanoic Acid ◽  
Contractile Activity ◽  
Subcutaneous Administration ◽  
Gastric Fundus ◽  
Lag Phase ◽  
Gastric Emptying Rate ◽  
Emptying Time

Sumatriptan, a 5-hydroxytryptamine1 (5-HT1) receptor agonist at enteric neuronal 5-HT receptors, causes a relaxation of the gastric fundus and inhibition of antral contractile activity. The present study examined the effect of sumatriptan on gastric emptying of solids and liquids in humans. In eight healthy subjects the gastric emptying rate for liquids and solids was measured using the carbon-labeled glycine and octanoic acid breath test after subcutaneous administration of placebo or sumatriptan. Sumatriptan increased the gastric half-emptying time of liquids (P < 0.0005) and induced a prolonged lag phase for liquids (P < 0.0005) in all subjects. Sumatriptan increased gastric half-emptying time (P < 0.005) and the lag phase of solids (P < 0.05) in all subjects. In two healthy subjects gastric emptying of liquids and solids after subcutaneous administration of sumatriptan was studied by radioscintigraphy. Radioscintigraphy confirmed the delayed emptying and the prolonged lag phases after sumatriptan. In conclusion, sumatriptan delays gastric emptying of solids and liquids in healthy subjects. Moreover, sumatriptan induces a lag phase for liquids. The mechanism by which sumatriptan alters gastric emptying remains to be studied.

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