Effect of distension and feeding on phasic changes in human proximal gastric tone.

BACKGROUND Proximal stomach by virtue of its property of accommodation acts as a reservoir for the ingested food, but its role in emptying and the factors modulating it remain unexplored. AIM To assess the effects of distension and of feeding on proximal gastric tone. SUBJECTS 14 healthy volunteers with no current or past history of any gastro-intestinal symptoms. METHODS Isobaric changes in volume of the proximal stomach were recorded both during fasting and for the first 30 minutes after a meal. RESULTS For a given degree of distension, the mean (SEM) intragastric pressure was consistently lower, immediately after meal ingestion (9.8 (1.1), mm Hg) than during fasting (12.9 (0.6) mm Hg; p < 0.01). Proximal gastric tone was continuously variable with a frequency of fluctuation of 0.9-1.3/minute and an amplitude of 16.8 (2.2) ml, superimposed upon slower higher amplitude fluctuations in baseline tone. These variations in tone were unaffected by the degree of gastric distension or by food. CONCLUSIONS While proximal gastric tone decreases after meal ingestions consistent with accommodation, the fluctuations in tone are not an importance factor in the modulation of nutrient emptying from the proximal stomach in the immediate postprandial period.