Pancreatic β cells: the metabolic network underlying body’s glucostat

Insulin secretion by pancreatic islet β cells is crucial to maintain normal blood glucose levels and thus body homeostasis in humans and many other animals. Insulin secretion is regulated by metabolic, endocrine, and paracrine mechanisms, the deregulation of which leads to several diseases, most noticeably type 2 diabetes. Therefore, it is of utmost importance to understand the mechanisms underlying insulin exocytosis from β cells. The initially described triggering pathway is nowadays recognized to be supported by the amplifying pathway that involves the participation of several metabolic intermediates. The complexity underlying the metabolism-insulin secretion coupling makes its comprehension challenging. Indeed, a network of several molecular players participate particularly in the amplifying pathway of the secretory response. This chapter summarizes the metabolic events that support the secretory function of β cells, emphasizing the coupling between glucose metabolism and insulin secretion, as well as the signaling pathways modulated by neurohormonal stimuli.