SUMMARY
A combined chemical and electron microscopic study of normal platelets and platelets from patients with the carcinoid syndrome has revealed an association between their serotonin content and certain alterations in their cytoplasmic structure. In addition to a fibrillary structure of possible cytoskeletal significance, platelets also contain a system of microtubules and vesicles. When the platelet serotonin content is high this tubular structure is prominent and communicates with large vacuoles which may contain granular material. Normal platelets incubated with serotonin show similar alterations in structure. In addition, serial investigations of platelets from two carcinoid patients suggest that in addition to the normal active transport process for absorbing serotonin a diffusion process can operate when the cell is exposed to high environmental concentrations. The significance of these storage mechanisms in relation to normal and elevated platelet serotonin concentration is discussed.
scite is a Brooklyn-based organization that helps researchers better discover and understand research articles through Smart Citations–citations that display the context of the citation and describe whether the article provides supporting or contrasting evidence. scite is used by students and researchers from around the world and is funded in part by the National Science Foundation and the National Institute on Drug Abuse of the National Institutes of Health.