Figure 1
From: Signaling mechanisms of glucose-induced F-actin remodeling in pancreatic islet β cells
Biphasic glucose-stimulated insulin secretion from perfused mouse islets. In response to a square-wave increase in glucose concentration, islet β cells dock/fuse ∼50–100 granules in the first phase of secretion. First phase is temporally defined, complete within ∼10 min of glucose stimulation, thought to be accounted for in large part by the readily releasable pool of granules. First phase is immediately followed by a second phase, with second phase being lower in amplitude but persistent in the presence of glucose stimulation over hours of time, and thus not temporally limited. Second phase is presumed to require storage/reserve pools of granules that can be recruited to the plasma membrane for secretion.
