Peripheral Cholecystokinin

This chapter discusses cholecystokinin (CCK) along with its associated peripheral actions associated. The new molecular forms of cholecystokinin from intestinal extracts in amounts and in purities are suitable for identification and assays of their biological activities. These new forms include CCK-83, CCK-58, CCK-22, and CCK-8. The peripheral actions of CCK can be divided into three categories, namely, regulation of a meal, other actions not directly influencing a meal, and pathophysiological actions. There are approximately 10 actions of endocrine peptides that have been firmly established as physiological. For CCK, two of those actions are the regulation of pancreatic secretion and gallbladder contraction. In addition, CCK is increasingly recognized as an inhibitor of gastric motility. One of the most interesting aspects of CCK is having different quantitative and qualitative expressions of biological activity for pancreatic secretion. However, humans and many other species do not have CCK-1 receptors on their pancreas, so CCK must act indirectly via receptors on vagal afferents or via other yet undiscovered indirect pathway.