Abstract
1. Infusions of oleic acid into the colon or the distal part of the ileum in anaesthetized cats inhibits secretion of water and amylase by the pancreas, stimulated by secretin and pancreozymin. Intraileal infusions of other non-water-soluble substances or hypertonic solutions can also inhibit the pancreas. 2. As inhibition can be produced after extrinsic denervation of the pancreas and gut, it must in part be humorally mediated. 3. Pentagastrin-stimulated gastric secretion of acid and pepsin is also inhibited by the intraileal infusions, but the inhibition of acid secretion is less than that of pancreatic secretion. 4. It is suggested that the physiological counterpart of the inhibitory effects induced by the infusion of non-physiological solutions into the colon or ileum is an inhibition of pancreatic secretion brought about by the cessation of intestinal absorption, which marks the completion of the post-prandial digestive process.