Overnight Culture Unmasks Glucose-induced Insulin Secretion in Mouse Islets Lacking ATP-sensitive K+ Channels by Improving the Triggering Ca2+ Signal

A current model ascribes glucose-induced insulin secretion to the interaction of a triggering pathway (KATP channel-dependent Ca2+ influx and rise in cytosolic [Ca2+]c) and an amplifying pathway (KATP channel-independent augmentation of secretion without further increase of [Ca2+]c). However, several studies of sulfonylurea receptor 1 null mice (Sur1KO) failed to measure significant effects of glucose in their islets lacking KATP channels. We addressed this issue that challenges the model. 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