Development and characterization of simulant pancreatic islets

• Published in: Analytical biochemistry 2003-03, Vol.314 (1), p.38-45
• Main Authors: Maghasi, Anne T., Schlueter, Kevin T., Halsall, H.Brian, Heineman, William R., Rodriguez Rilo, Horacio L.
• Format: Article
• Language: English
• Subjects: Animals; Anodic stripping voltammetry; Dogs; Electrochemistry; Hydrochloric Acid - pharmacology; Insulin - metabolism; Insulin Secretion; Islets of Langerhans - drug effects; Islets of Langerhans - metabolism; Microspheres; Pancreatic islets; Rats; Sepharose - metabolism; Sepharose - pharmacology; Simulant beads; Staining and Labeling; Zinc; Zinc - metabolism
• ISSN: 0003-2697; 1096-0309
• DOI: 10.1016/S0003-2697(02)00626-7

Insulin is stored in pancreatic islets as a zinc–insulin complex, and stimulating the islets results in the release of insulin and zinc. Simulant pancreatic islet beads have been developed using agarose beads (50–250 μm diameter) derivatized with iminodiacetic acid that have been loaded with zinc. A qualitative comparison of the simulant beads with pancreatic islets has been made by staining with dithizone and a zinc-binding fluorescent dye, TSQ. The binding capacity of simulant beads was determined to be 34 μmol Zn 2+/g of dried beads using anodic stripping voltammetry. Hydrochloric acid was used to release zinc from beads to mimic the secretion of insulin from pancreatic islets and a release profile was established. The simulant beads can be used to optimize the islet isolation process and reduce the use of real islets in method development.