Lazarus N R, Davis B, O'Connor K J
J Physiol (Paris). 1976 Nov;72(6):787-94.
By the use of an in vitro insulin releasing system, new insights into the meechanisms underlying the insulin exocytotic process have been gained. It is proposed that insulin release is initiated by glucose interacting with a glucoreceptor on the plasma membrane. Some properties of this receptor are discussed. It is postulated that after initiation of secretion, continued insulin release is under the control of phosphorylated intermediates of glucose metabolism, i.e. glucose-6-phosphate and phosphoenol pyruvate, operating via a membrane-bound protein kinase. The initiation of insulin release by glucose, and the augmentation of this initiation by the above mentioned intermediates, is viewed as a modified cascade system. The cascade theory of insulin secretion is postulated as an alternative to the threshold distribution hypothesis of insulin secretion. The action of tolbutamide in relation to the two pool theory of insulin secretion is discussed.
通过使用体外胰岛素释放系统，人们对胰岛素胞吐过程的潜在机制有了新的认识。有人提出，胰岛素释放是由葡萄糖与质膜上的葡萄糖受体相互作用引发的。讨论了该受体的一些特性。据推测，在分泌开始后，胰岛素的持续释放受葡萄糖代谢的磷酸化中间产物（即6-磷酸葡萄糖和磷酸烯醇丙酮酸）的控制，这些中间产物通过一种膜结合蛋白激酶起作用。葡萄糖引发胰岛素释放以及上述中间产物增强这种引发作用，被视为一种改良的级联系统。胰岛素分泌的级联理论被假定为胰岛素分泌阈值分布假说的替代理论。还讨论了甲苯磺丁脲与胰岛素分泌的双池理论相关的作用。
