Evidence for defective glucose sensing by islets of ...
Description
Citation
| Title | Evidence for defective glucose sensing by islets of fa/fa obese Zucker rats |
| Author(s) | C. Chan, R. MacPhail, K. Mitton |
| Journal | Canadian journal of physiology and pharmacology |
| Date | 1993 |
| Volume | 71 |
| Issue | 1 |
| Start page | 34 |
| End page | 39 |
| Abstract | The hypothesis that a defect in glucose sensing by islets of fa/fa Zucker rats contributes to hyperinsulinemia in these animals was tested. Islets from lean and fa/fa rats were isolated by collagenase digestion and step-density gradient purification and then cultured overnight in Dulbecco's modified Eagle's medium containing 12.5 mM glucose. Obese rat islets were more sensitive to hypoglycemic glucose levels with half-maximal effective concentration (EC50) of 5.6 mM compared with an EC50 of 8.2 mM for lean rat islets. In contrast, responsiveness of both phenotypes to alpha-ketoisocaproate and quinine was similar. Mannoheptulose did not inhibit insulin secretion from fa/fa islets, although inhibitors of later events in the stimulus-secretion coupling pathway were normally inhibited by iodoacetate and diazoxide. Finally, starvation in vivo and culture of islets in low glucose concentrations (5 mM) in vitro both decreased glucose-stimulated insulin secretion from lean but not fa/fa rat islets. We conclude that fa/fa rat islets have an exaggerated insulin response to hypoglycemic stimuli, possibly as a result of a defect in B-cell glucokinase function. |
| ISSN | 0008-4212 |
Using APA 6th Edition citation style.
[Page generation failure. The bibliography processor requires a browser with Javascript enabled.]
Times viewed: 58
