The ins and outs of fatty acids on the pancreatic β cell

Long-chain fatty acids (FAs) augment glucose-induced insulin secretion from the pancreatic P cell via intracellular metabolism and generation of lipid-derived molecules. The recent observation, simultaneously reported by three independent groups, that long-chain FAs activate GPR40, a G-protein-coupled cell-surface receptor, indicates that they can also act as extracellular receptor ligands. The physiological relevance of this novel mechanism of action of FAs remains to be confirmed.