Monitor peptide
Monitor peptide, also known as pancreatic secretory trypsin inhibitor I or pancreatic secretory trypsin inhibitor 61, is a peptide that plays an important role in the regulation of the digestive system, specifically the release of cholecystokinin.
Function
One of the primary functions of monitor peptide is to stimulate the release of CCK from the enteroendocrine cells of the small intestine. CCK then acts on the gallbladder to release bile and on the pancreas to release digestive enzymes, which help to further break down the food. This coordinated response helps to ensure efficient digestion and absorption of nutrients.Another function is to act as a competitive inhibitor of trypsin, which is a protease that can activate other proteases. It has been shown to prevent premature activation of pancreatic enzymes.
Its role as a feedback regulator has been well-described for decades. Monitor peptide binds to intestinal epithelial cells and induces CCK-release, which enhances pancreatic secretion in the presence of nutritional protein in the duodenum. When all nutritional protein is digested, monitor peptide is bound by trypsin and subsequently degraded, resulting in decreasing CCK-release and a reduction of pancreatic secretion.