Influence of acid-pepsin secretion on gastric emptying of solids in humans: studies with cimetidine.

The commonly accepted model for gastric emptying suggests that the 'antral mill' is responsible for the triturition and subsequent emptying of solid food from the stomach. Little is known about the contribution to solid emptying made by other digestive mechanisms such as acid-pepsin secretion. We have investigated the effect of inhibiting gastic secretion on the rate at which a solid test meal emptied from the stomach. Using a radiolabelled beefburger, we performed paired gammacamera studies on consecutive days in 10 fasted, healthy volunteers to compare gastric emptying of the test meal with and without oral cimetidine (400 mg 1 hour before the test, 800 mg at the start of the meal). Inhibition of acid-pepsin secretion by cimetidine was associated with an appreciable delay in the rate of emptying of the burger from the stomach (T50 cimetidine 187 (16) min (mean (SEM); T50 no cimetidine 146 (15) min; p less than 0.01, paired t test). This delay was related to a change in the slope of the emptying profile and was not associated with a prolonged lag phase. These results may be explained by the relative achlorhydria and reduced pepsin activity induced by cimetidine impairing the breakdown of solid food into particles small enough to leave the stomach.