Glucose Responsiveness of β-Cells Depends on Fatty Acids
This study examined the influence of bovine serum albumin (BSA)-coupled fatty acids on GSIS. Isolated islet preparations of human donors and of 12-months old mice displayed impaired GSIS in the presence of 0.5% FFA-free BSA compared to 0.5% BSA (fraction V, not deprived from fatty acids). In aged INS-1E cells, i. e. at a high passage number, GSIS became highly sensitive to FFA-free BSA. Readdition of 30 µM palmitate or 30 µM oleate to FFA-free BSA did not rescue GSIS, while the addition of 100 µM palmitate and the raise of extracellular Ca2+from 1.3 to 2.6 mM improved glucose responsiveness. A high concentration of palmitate (600 µM), which fully activates FFA1, largely restored insulin secretion. The FFA1-agonist TUG-469 also increased insulin secretion but to a lesser extent than palmitate. Glucose- and TUG-induced Ca2+oscillations were impaired in glucose-unresponsive, i. e., aged INS-1E cells. These results suggest that fatty acid deprivation (FFA-free BSA) impairs GSIS mainly through an effect on Ca2+sensitivity. [...] © Georg Thieme Verlag KG Stuttgart · New YorkArticle in Thieme eJournals: Table of contents | Abstract | Full text
Source: Experimental and Clinical Endocrinology and Diabetes - Category: Endocrinology Authors: Gerst, Felicia Singer, Christine Noack, Katja Graf, Dunia Kaiser, Gabriele Panse, Madhura Kovarova, Marketa Schleicher, Erwin H äring, Hans-Ulrich Drews, Gisela Ullrich, Susanne Tags: Article Source Type: research