title: Relaxation responses of the human proximal stomach to distension during fasting and after food.
abstract: The responses of the human proximal stomach to distension were studied in 22 healthy volunteers using an intragastric polyethylene bag, inflated progressively in 30-ml steps until the limit of tolerated volume was reached. Three successive inflations were carried out during the fasting state followed by a fourth inflation after ingestion of 250 ml of either a nutrient meal or isosmolar saline. The first inflation showed an initial nonlinear pressure rise (slope of logged pressure vs. volume = 114.6 +/- 10.0 log mmHg/ml x 10(-5)), which was then followed by the development of a plateau phase, in which further distension did not increase intragastric pressure. The slopes of the subsequent fasting inflations were significantly lower than that of the first inflation (P < 0.01) but were similar to each other (slope 83.0 +/- 5.4 and 79.8 +/- 5.7 log mmHg/ml x 10(-5)), indicating that distension-induced gastric relaxation had occurred. After saline ingestion, responses to distension were similar to those during the fasted state. After the nutrient meal ingestion, however, the slope decreased to 60.3 +/- 7.7 log mmHg/ml x 10(-5) (P < 0.01 vs. saline), indicating nutrient-induced gastric relaxation. Our study demonstrates that the pressure-volume characteristics of the proximal stomach are modulated both by distension and by the presence of nutrients in the upper gut, which appear to operate independently.
authors.affiliation: Department of Medicine, University of Manchester Medical School, Hope Hospital, United Kingdom.
authors.forename: N K
authors.initials: NK
authors.lastname: Ahluwalia
authors.forename: D G
authors.initials: DG
authors.lastname: Thompson
authors.forename: J
authors.initials: J
authors.lastname: Barlow
authors.forename: L E
authors.initials: LE
authors.lastname: Troncon
authors.forename: S
authors.initials: S
authors.lastname: Hollis
mesh_terms: D000328:Adult; D002404:Catheterization; D004326:Drinking; D004435:Eating; D005215:Fasting; D005260:Female; D006801:Humans; D008297:Male; D009126:Muscle Relaxation; D011312:Pressure; D012965:Sodium Chloride; D013270:Stomach / Q000502:physiology*
chemical_list: D012965:Sodium Chloride