ISSN:
1432-0878
Keywords:
Pancreatic β-cells (mouse)
;
Formation and storage of insulin
;
Role of zinc and calcium
;
Culture of islets
;
Electron microscopy
Source:
Springer Online Journal Archives 1860-2000
Topics:
Biology
,
Medicine
Notes:
Summary 1. The effects of culture of isolated mouse islets of Langerhans for up to 9 days in media which had been depleted of zinc electrochemically or with the chelating agent Tris-(2-aminoethyl) amine, or of calcium, have been compared. 2. An 83% reduction of extracellular zinc concentration did not adversely affect proinsulin biosynthesis, conversion of proinsulin to insulin, or the ability of cells to store newly formed insulin in granules. When incubation media were depleted of both zinc and calcium the β-cells produced abnormally large electron-lucent granules, consistent with the failure of insulin to crystallise within the granule sac. 3. Very similar results, with formation of large electron lucent granules, were obtained after culture of islets in the absence of calcium but in the presence of normal concentrations of zinc. 4. It is suggested that zinc may play a less critical role in the biosynthesis of proinsulin and its conversion to insulin, while calcium may have a more important function in insulin storage, than has sometimes previously been supposed.
Type of Medium:
Electronic Resource
URL:
http://dx.doi.org/10.1007/BF00220518
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