Regulatory peptides in endocrine cells and autonomic nerves: electron immunocytochemistry

Advances in immunocytochemistry, particularly at the electron microscope level, have enabled us to establish further details of the ultrastructural appearance of endocrine cells and autonomic nerves of the gastrointestinal tract. Its contribution can be summarised as follows: a)validation of previously recognised endocrine cell types. b) Recognition of sub-groups within endocrine cells and autonomic nerve cell types previously included within one single type (e.g. D1 cells and p-type autonomic nerves). c) Discrimination of molecular forms now known to be stored in morphologically distinguishable secretory granules or parts thereof (e.g. pro-glucagon and glucagon in A cells and gut and antral gastrin-producing cells). Advances in the techniques and the accurate quantification of the end products will enable us to recognise changes in gastrointestinal tract diseases in man.