Cellular action of gastrointestinal polypeptide hormones

The present state of chemistry, structure-activity relationship and cellular mode of action of gastrointestinal polypeptide hormones (gastrin, secretin, cholecystokinin-pancreozymin, caerulein and bombesin) are reviewed. Possible structure of polypeptide receptors and the mechanism of peptide--receptor interaction are described, and the role of acetylcholine and histamine in secretion discussed. The present data support the hormonal-receptor significance of cyclic nucleotides (cAMP, cGMP) in the cellular regulation of secretion.