Fat preload delays gastric emptying: reversal by cisapride

1. Meals empty more slowly when they contain fat. 2. This study investigated whether an intragastric fat preload in comparison with a water preload affected gastric emptying of a semisolid meal and antral motor activity, and whether cisapride reversed such effects. 3. Twelve healthy subjects were studied under three conditions each: (A), preload of 50 ml water orally; (B) and (C), preload of 50 ml cream (20 g fat). After preloads, subjects reclined right sided for 20 min. Thereafter, placebo in conditions (A) and (B) and 10 mg cisapride in (C) were administered i.v. in a random double-blind fashion and subjects ingested a semisolid radiolabelled 1150 kJ meal. Gastric emptying and antral motor activity were recorded scintigraphically for 50 min using a dual-headed gamma camera. 4. Gastric emptying was significantly slower (P less than 0.005) after fat preload and placebo than after water preload and placebo. Cisapride administered after fat preload abolished the delaying effect of the fat preload (P less than 0.001). 5. Antral contraction amplitudes after fat preload and placebo were higher (P less than 0.01) than after water preload and placebo as well as fat preload and cisapride at the start of recording and decreased slightly thereafter, whereas slight increases occurred in the other conditions. Frequency and propagation velocity of contractions were not differently affected. 6 Gastric emptying is delayed after prior fat ingestion and this effect is abolished by cisapride.