Intragastric infusion of chlorhydric acid (HCl) potentiates gastric sensitivity to gastric distension in man

The involvement of 5-hydroxytryptamine3 (5-HT3) receptors in gastric motor and sensory responses to distension and duodenal lipid was investigated. Subjects were studied on four occasions during which isotonic saline or 20% Intralipid (2 kcal/ml) was infused intraduodenally (1 ml/min) while the proximal stomach was distended with air (100 ml/min). Subjects received either 8 mg ondansetron (5-HT3 antagonist) or placebo orally in random order. Intragastric pressure was recorded continuously, and subjects reported gastric sensations. Gastric motor and sensory responses to distension during duodenal saline were similar with placebo and ondansetron. Intraduodenal lipid decreased gastric tonic and phasic pressure activity, and this was not influenced by ondansetron. Lipid also induced meal-like fullness followed by nausea during distensions. Ondansetron reduced nausea and did not affect meal-like fullness but increased volumes and pressures at which sensations were reported. Intestinal 5-HT3 receptors are involved in induction of nausea but not of meal-like fullness by intraduodenal lipid and gastric distension. 5-HT3 receptor antagonism reduces gastric sensitivity to distension during intraduodenal lipid infusion.

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Gastric mechanosensory and lower esophageal sphincter function in rumination syndrome

AJP Gastrointestinal and Liver Physiology ◽

10.1152/ajpgi.1998.275.2.g314 ◽

1998 ◽

Vol 275 (2) ◽

pp. G314-G321 ◽

Cited By ~ 16

Author(s):

Miriam Thumshirn ◽

Michael Camilleri ◽

Russell B. Hanson ◽

Donald E. Williams ◽

Alfred J. Schei ◽

...

Keyword(s):

Lower Esophageal Sphincter ◽

Pain Perception ◽

Motor Dysfunction ◽

Gastric Distension ◽

Gastric Accommodation ◽

Standard Meal ◽

Sphincter Function ◽

Rumination Syndrome ◽

Gastric Sensitivity ◽

Esophageal Sphincter

Our hypothesis was that rumination syndrome is associated with gastric sensory and motor dysfunction. We studied gastric and somatic sensitivity, reflex relaxation of the lower esophageal sphincter (LES), and gastric compliance and accommodation postprandially and postglucagon. A barostatically controlled gastric bag and esophageal manometry were used to compare gastric sensorimotor functions and LES relaxation to gastric distension in 12 patients with rumination syndrome and 12 controls. During bag distensions, patients had greater nausea, bloating, and aggregate score, but not pain, compared with controls ( P < 0.05). At 4 and 8 mmHg gastric distension, LES tone reduction was greater in patients than in controls ( P < 0.05). Gastric compliance, accommodation to a standard meal, and response to glucagon were not different in patients and controls; however, 6 of 12 patients had no gastric accommodation; the latter patients had significantly greater pain perception during distension ( P < 0.05) but normal somatic sensitivity compared with healthy controls. Rumination syndrome is characterized by higher gastric sensitivity and LES relaxation during gastric distension. A subgroup of patients also had absent postprandial accommodation.

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Intraluminal modulation of gastric sensitivity to distension: effects of hydrochloric acid and meal

AJP Gastrointestinal and Liver Physiology ◽

10.1152/ajpgi.2001.280.5.g904 ◽

2001 ◽

Vol 280 (5) ◽

pp. G904-G909 ◽

Cited By ~ 14

Author(s):

Benoit Coffin ◽

Robert Chollet ◽

Bernard Flourié ◽

Marc Lémann ◽

Claire Franchisseur ◽

...

Keyword(s):

Hydrochloric Acid ◽

Gastric Acid ◽

Healthy Subjects ◽

Gastric Distension ◽

Wall Tension ◽

Maximal Volume ◽

Acid Infusion ◽

Fixed Volume ◽

Gastric Sensitivity ◽

Meal Ingestion

Conscious sensations in response to gut distensions may be modulated by temporospatial interactions among different stimuli. This study investigated whether symptoms induced by gastric distension may be modified by hydrochloric acid (HCl) gastric infusion and meal ingestion. In nine healthy subjects, fixed pressure (isobaric) and fixed volume (isovolumetric) distensions were performed during continuous (4 ml/min) intragastric saline or HCl infusion, during fasting and after meal ingestion, until the maximal distension step defined as discomfort or a predefined maximal volume. During fasting isobaric distensions, the maximal distension step was significantly decreased during HCl compared with saline. The intragastric volumes were not significantly different, but the wall tension was significantly lower during HCl than saline. HCl increased gastric compliance. Meal ingestion relaxed the stomach and decreased the pressure at the maximal distension step during saline, but HCl did not further decrease it compared with fasting. During isovolumetric distensions, HCl also increased gastric compliance, but in both fasted and fed states it did not modify the maximal distension steps. In conclusion, sensations in response to gastric isobaric distensions, but not to isovolumetric distensions, are influenced by gastric acid infusion and meal ingestion. The effects of HCl might be related to a sensitization of mucosal mechanoreceptors.

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