Generation of Gastroesophageal Reflux Disease Symptoms During Esophageal Acid Infusion With Concomitant Esophageal pH Monitoring in Healthy Adults

BACKGROUND/AIMS: The sensitivity of the upper and lower esophageal mucosa to acid is considered to differ. We investigated the relationship between pH changes in different sites of the esophagus and generation of gastroesophageal reflux symptoms during an acid infusion test. METHODS: An acid infusion catheter was placed at 5 or 15 cm above the lower esophageal sphincter (LES) in 18 healthy volunteers, while a 2-channel pH sensor catheter was also placed in each with the sensors set at 5 and 15 cm above the LES. Solutions containing water and hydrochloric acid at different concentrations were infused through the infusion catheter. RESULTS: Acid infusion in the upper esophagus caused a pH drop in both upper and lower esophageal sites, whereas that in the lower esophagus resulted in a significant pH drop only in the lower without a corresponding pH decline in the upper esophagus. Stronger heartburn, chest pain, and chest oppression symptoms were noted when acid was infused in the upper as compared to the lower esophagus, while increased intra-esophageal acidity strengthened each symptom. Regurgitations caused by upper and lower esophageal acid infusions were similar, and not worsened by a larger drop in intra-esophageal pH. Chest pain was caused only by lowered intra-esophageal pH, while heartburn, chest oppression, and regurgitation were induced by a less acidic solution. CONCLUSIONS: Higher intra-esophageal acidity caused stronger heartburn, chest pain, and chest oppression symptoms. However, regurgitation was not significantly influenced by intra-esophageal acidity. The upper esophagus showed higher acid sensitivity than the lower esophagus.

Effects of Rikkunshito (TJ-43) on Esophageal Motor Function and Gastroesophageal Reflux

BACKGROUND/AIMS: Rikkunshito (TJ-43), an herbal medicine, has been demonstrated to relieve gastroesophageal reflux symptoms. However, the effects of TJ-43 on esophageal motor functions have not been fully determined. This double-blind crossover study was performed to investigate the effects of TJ-43 on esophageal motor functions and gastroesophageal reflux. METHODS: The subjects were 10 normal male volunteers. Lower esophageal sphincter pressure and esophageal body peristaltic contractions with and without 1-week administration of TJ-43 were examined in a crossover fashion. Post-prandial gastroesophageal reflux was also determined using a multi-channel impedance pH dual monitor. RESULTS: TJ-43 at a standard dose of 7.5 g/day did not significantly augment esophageal peristaltic contraction pressure measured in the proximal, middle and distal segments of the esophagus, whereas increment of resting lower esophageal sphincter pressure was observed in a supine position. In addition, TJ-43 administration did not decrease post-prandial gastroesophageal acid, non-acid reflux events or accelerate esophageal clearance time. CONCLUSIONS: TJ-43 at a standard dose did not have a significant effect on esophageal motor activity or gastroesophageal reflux in healthy adults.

Influence of Full-body Water Immersion on Esophageal Motor Function and Intragastric Pressure

BACKGROUND/AIMS: In Japan, it is customary to take a daily bath during which the body is immersed in water to the neck. During full-body immersion, hydrostatic pressure is thought to compress the chest and abdomen, which might influence esophageal motor function and intra-gastric pressure. However, whether water immersion has a significant influence on esophageal motor function or intragastric pressure has not been shown. The aim of this study was to clarify the influence of full-body water immersion on esophageal motor function and intragastric pressure. METHODS: Nine healthy male volunteers (mean age 40.1 +/- 2.8 years) were enrolled in this study. Esophageal motor function and intragastric pressure were investigated using a high-resolution 36-channel manometry device. RESULTS: All subjects completed the study protocol. Intragastric pressure increased significantly from 4.2 +/- 1.1 to 20.6 +/- 1.4 mmHg with full-body water immersion, while the lower esophageal high pressure zone (LEHPZ) value also increased from 20.5 +/- 2.2 to 40.4 +/- 3.6 mmHg, with the latter being observed regardless of dietary condition. In addition, peak esophageal peristaltic pressure was higher when immersed as compared to standing out of water. CONCLUSIONS: Esophageal motor function and intragastric pressure were altered by full-body water immersion. Furthermore, the pressure gradient between LEHPZ and intragastric pressures was maintained at a high level, and esophageal peristaltic pressure was elevated with immersion.