[Gastrointestinal endocrine cells: brief history and main identification methods under light microscopy]

The gastrointestinal tract shows a wide spectrum of endocrine cells diffusely distributed along the mucosa, interspersed among the exocrine cells. These cells share several features such as the capacity to produce a series of peptides. Despite the development of digestive endocrinology, especially in the last decade and with respect to the biochemical knowledge and cellular localization of gastrointestinal regulatory peptides, their functional significance and their role in digestive phisiopathology remain partially unknown. This review represents a summary of the principal information about morphological and histochemical features, embryologic origin, historical data, methods of identification and types of endocrine cells, of gastrointestinal tract.