title: Regional postprandial differences in pH within the stomach and gastroesophageal junction.
abstract: Our objective was to determine regional differences in intragastric pH after different types of meals. Ten normal subjects underwent 27-hr esophagogastric pH monitoring using a four-probe pH catheter. Meals were a spicy lunch, a high-fat dinner, and a typical bland breakfast. The fatty dinner had the highest postprandial buffering effect, elevating proximal and mid/distal gastric pH to 4.9 +/- 0.4 and 4.0 +/- 0.4, respectively, significantly (P < 0.05) higher compared to 4.2 +/- 0.3 and 3.0 +/- 0.4 for the spicy lunch and 3.0 +/- 0.3 and 2.5 +/- 0.8 for the breakfast. The buffering effect of the high-volume fatty meal to pH > 4 was also longer (150 min) compared to that of the spicy lunch (45 min) and the bland breakfast, which did not increase gastric pH to > 4 at any time. Proximal gastric acid pockets were seen between 15 and 90 min postprandially. These were located 3.4 +/- 0.8 cm below the proximal LES border, extending for a length of 2.3 +/- 0.8 cm, with a drop in mean pH from 4.7 +/- 0.4 to 1.5 +/- 0.9. Acid pockets were seen equally after the spicy lunch and fatty dinner but less frequently after the bland breakfast. We conclude that a high-volume fatty meal has the highest buffering effect on gastric pH compared to a spicy lunch or a bland breakfast. Buffering effects of meals are significantly higher in the proximal than in the mid/distal stomach. Despite the intragastric buffering effect of meals, focal areas of acidity were observed in the region of the cardia-gastroesophageal junction during the postprandial period.
authors.affiliation: The Gastroenterology Section, Department of Medicine, Temple University Hospital, Philadelphia, Pennsylvania 19140, USA.
authors.forename: Hrair P
authors.initials: HP
authors.lastname: Simonian
authors.forename: Lien
authors.initials: L
authors.lastname: Vo
authors.forename: Siva
authors.initials: S
authors.lastname: Doma
authors.forename: Robert S
authors.initials: RS
authors.lastname: Fisher
authors.forename: Henry P
authors.initials: HP
authors.lastname: Parkman
mesh_terms: D000328:Adult; D004943:Esophagogastric Junction / Q000502:physiology*; D005260:Female; D005744:Gastric Acid / Q000378:metabolism*; D005745:Gastric Acidity Determination; D005753:Gastric Mucosa / Q000378:metabolism*; D005773:Gastroscopy; D006801:Humans; D006863:Hydrogen-Ion Concentration; D008297:Male; D019518:Postprandial Period / Q000502:physiology; D011446:Prospective Studies; D012016:Reference Values; D012680:Sensitivity and Specificity