The gastric emptying of sucrose and maltose solutions at different concentrations, with addition of phenol red (6 mg%) used as a marker, was studied in 144 Wistar male rats. The gastric retention was determined 15 minutes after the orogastric infusion of sucrose and maltose solutions at 2.5%, 5% and 10% and volume of 1 and 2 ml/100 g weight of the animal, making 1 use of 12 rats for each volume and concentration. The activities of lactase, sucrase and maltase were evaluated in other eight rat's small intestine. The results demonstrated a maltase/sucrase activity rate of 4:1. The gastric retentions of the maltose solution were significantly higher than sucrose solution at 10% and 5% concentration, either 1 and 2 ml/100 g weight. There were no differences between gastric retention at 2.5% concentration neither with 2 nor 1 ml/100 g weight. As an explanation of these results it is proposed that the faster gastric emptying of sucrose solution 10% and 5% in relation with the same concentrations of maltose is due to a probable saturation of sucrase, that when achieved, interrupts the regulation of gastric emptying, determined by the intestinal receptors.
Animals Disaccharidases