Effect of prolonged intraluminal α-amylase inhibition on eating, weight, and the small intestine of rats

Effects of chronic intraluminal amylase inhibition on eating and the digestive system are unclear. In growing rats, we determined the effect of ingesting a wheat amylase inhibitor (AI) on eating, weight, small intestinal mucosal growth, and disaccharidases. Three groups of 12 rats received AI, were pair-fed controls (PFC), or had free access to food (FAC). After measuring food intake and body and stool weight for 21 d, rats were decapitated and the small intestine was divided into four segments. AI and PFC rats had similar food intake, weight gain, and stool output, but these were less than FAC rats (P < 0.005). AI rats ate less (P < 0.001) than PFC during the light cycle and less than FAC rats during darkness. Mucosal DNA and RNA were reduced (P < 0.05) in the upper small intestine of AI and PFC rats compared with FAC rats. Mucosal weight, RNA, and disaccharidase activities were greater (P < 0.01) in the ileum of AI rats compared with PFC and FAC rats. AI alters the amount and pattern of food intake, reduces weight gain, upper small intestinal mucosal weight, protein and DNA, and increases distal small intestinal mucosal weight, RNA, and disaccharidases. AI likely causes these effects by inducing satiety and increasing carbohydrate delivery to the distal intestine.