[Advances in gastrointestinal peptides: gastrin]

Classical hormones (present in blood circulation), neuro-endocrine agents (released in the neural synapses), paracrine substances (disseminated around neighbouring cells) and autocrine factors (acting upon its own generating cell) constitute the universe of gastrointestinal peptides. Early gastrointestinal endocrinology has progressed into the current "receptorology" age. Technological advances have naturally produced an almost alluvial amount of information. This review addresses to several features of gastrin, a member of the gastrin/cholecystokinin family: a) participation in the regulation of gastric acid secretion; b) secretory cells receptors; c) hypergastrinemia and its influence upon enterochromaffin-like cells in characteristic clinical situations; d) histamine release regulation; and e) gastrin receptors and their potential actions on normal and neoplastic colonic epithelium.