Gastrointestinal hormones and apudomas

Interest and developments in gastrointestinal hormones 'exploded' since gastrin was isolated by Gregory et al in 1964. Progress in radioimmunoassay and chromatography was responsible for the 'unleashing' of peptides whose nomenclature and properties were scarcely defined before newer peptides were identified and reported. And still, it sometimes seems that there are more peptides than chemical effects attributed to them. In this review are discussed: the cells of origin; their mechanism of action; gastrin with its actions and applications; secretin; cholecystokinin-pancreozymin; gut glucagon (enteroglucagon); VIP and SIP; and finally bombesin and other candidate hormones. The latter are mentioned: chymodenin; avian pancreatic polypeptide (APP); coherin; urogastrone; bulbogastrone and enteroxyntin. The variety of peptides and hormones which arise from the intestinal tract has rapidly increased in the past 10 yr. Radioimmunoassays will be developed for all of them and clinical applications or physiologic functions will be identified. Perhaps the next step will be synthesis of these substances so that clinical use may stimulate deficient biochemical actions or treat clinical syndromes caused by excess production of circulating peptides.