RX871024 but not Efaroxan stimulates insulin secretion by a KATP independent mechanism

Introduction: Within a certain concentration range the first generation imidazoline, RX871024, enhances insulin release only when the glucose concentration by itself is stimulatory (glucose-selectivity). This effect was ascribed to the activation of a KATP channel-independent pathway in addition to the direct closure of KATP-channels. Here we show that efaroxan, another glucose-selective, first generation imidazoline, produces an insulinotropic effect only via the KATP channel-dependent pathway and has no effect on insulin release from Sur1KO islets that lack KATP channels. Methods: Three parameters were measure…