title: Isolation and properties of secretory granules from rat islets of Langerhans. II. Ultrastructure of the beta granule.
abstract: Beta granules isolated from rat islets of Langerhans and subjected only to phosphotungstic acid had, in negatively stained images, a 50-A periodicity. This periodicity was also observed in thin-section profiles of beta granules in intact cells. In shadowed preparations, the granules were spherical in shape and had irregular edges and surface structure. The presence of such a periodicity in the beta granule indicates that its matrix may be composed of a crystalline material.
mesh_terms: D000818:Animals; D002499:Centrifugation, Density Gradient; D003460:Crystallization; D003594:Cytoplasmic Granules; D007515:Islets of Langerhans / Q000166:cytology*; D008566:Membranes; D008854:Microscopy, Electron; D051381:Rats