Glucose decreases extracellular adenosine levels in isolated mouse and rat pancreatic islets

Yang, G. K. and Squires, Paul E. and Tian, Faming and Kieffer, T. J. and Kwok, Y. N. and Dale, Nicholas (2012) Glucose decreases extracellular adenosine levels in isolated mouse and rat pancreatic islets. Islets, 4 (1). pp. 64-70. ISSN 1938-2014

Full content URL: http://dx.doi.org/10.4161/isl.4.1.19037

Documents
Islets-2012-Adenosine.pdf

Request a copy
[img] PDF
Islets-2012-Adenosine.pdf - Whole Document
Restricted to Repository staff only

831kB
Item Type:Article
Item Status:Live Archive

Abstract

The pancreatic islets of Langerhans are responsible for the regulated release of the endocrine hormones insulin and glucagon that participate in the control of glucose homeostasis. Abnormal regulation of these hormones can result in glucose intolerance and lead to the development of diabetes. Numerous efforts have been made to better understand the physiological regulators of insulin and glucagon secretion. One of these regulators is the purine nucleoside, adenosine. Though exogenous application of adenosine has been demonstrated to stimulate glucagon release and inhibit insulin release, the physiological significance of this pathway has been unclear. We used a novel 7 µm enzyme-coated electrode biosensor to measure adenosine levels in isolated rodent islets. In the mouse islets, basal adenosine levels in the presence of 3 mM glucose were estimated to be 5.7 ± 0.6 µM. As glucose was increased, extracellular adenosine diminished. A 10-fold increase of extracellular KCl increased adenosine levels to 16.4 ± 2.0 µM. This release required extracellular Ca2+ suggesting that it occurred via an exocytosis-dependent mechanism. We also found that while rat islets were able to convert exogenous ATP into adenosine, mouse islets were unable to do this. Our study demonstrates for the first time the basal levels of adenosine and its inverse relationship to extracellular glucose in pancreatic islets.

Keywords:Islets, bmjdoi
Subjects:Library of Congress Subject Areas > Q Science > Q Science (General)
Divisions:College of Science > School of Life Sciences
ID Code:14063
Deposited On:02 Mar 2012 10:15

Repository Staff Only: item control page