CHAPTER 139 – Peripheral Cholecystokinin

As we enter the second century of cholecystokinin (CCK) research, it is apparent that there is still much to learn about the biochemistry, physiology, and pathophysiology of this gut peptide. For many hormones, peptide processing of a single gene product can result in multiple secreted molecular forms. For cholecystokinin, recent studies suggest that although there are many possible enzymatic processing products of preprocholecystokinin only one appears as a major circulating form (CCK-58). If these findings are confirmed and shorter forms of cholecystokinin are not only absent from mammalian tissues but are also aberrant in their actions compared to endogenous natural CCK, then past conclusions on the role of cholecystokinin in gut physiology will have to be reconsidered.