Amylin and the gastrointestinal tract.

There is increasing evidence that alterations in the rate of gastric emptying - both acceleration and slowing - are present in patients with diabetes mellitus. A number of different factors can influence the rate of gastric emptying. For example, a large meal volume, a high-fat meal, and the presence of high glucose concentrations will all slow the rate at which the contents of the stomach are emptied into the small intestine. Studies in spontaneously diabetic BB/Wistar rats have shown that administration of the pancreatic islet hormone amylin slows the rate of gastric emptying, and similar observations have been made in patients with Type 1 diabetes who received an intravenous infusion of the human amylin analogue pramlintide. The mechanism by which amylin slows gastric emptying is still unknown, but evidence from studies in animals suggests that it may influence the parasympathetic input to the stomach via neurons in the brainstem which regulate efferent activity in the vagus nerve.