Nanoscale amperometry reveals vesicular serotonin release from pancreatic beta cells is not all or none
Paper ID : 1103-ICNS
Authors:
Amir Hatamie *
Abstract:
Pancreatic beta-cells secrete insulin in response to elevated glucose concentrations and during beta-cell failure these cells secrete inadequate amounts of insulin leading to diabetes. Generally, Insulin is stored inside secretory nano granules (100-300 nm) which are called vesicles and quantitative estimations of insulin vesicle content and released insulin are nearly impossible. One means of understanding the process of insulin release is to measure serotonin or 5-hydroxytryptamine (5-HT) that is also stored in beta-cell vesicles and can be amperometrically determined with nanoelectrodes as it is co-released with insulin. Single beta cells preloaded with 5-HT were analysed with intracellular vesicle impact electrochemical cytometry (IVIEC) by using nanotip electrodes (D: 100-400 nm) for detection of stored 5-HT inside of vesicles in the intracellular space and by single-cell amperometry (SCA) by using microelectrodes (D: 5 ┬Ám) to determine released 5-HT in the extracellular space. The results show about 15 percent of accumulated 5-HT is released from secretory vesicles. Hence, beta-cell vesicles did not release their entire content during exocytosis, which might open new ways for diabetic treatment.
Keywords:
Diabetes, Single cell, Nano granule, Nano electrode, Electrochemistry.
Status : Abstract Accepted (Oral Presentation)