Intra- and inter-islet synchronization of metabolically driven insulin secretion
Intra- and inter-islet synchronization of metabolically driven insulin secretion
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DOI：
10.1529/biophysj.104.055681
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发表时间：
2005-07-01
影响因子：
3.4
通讯作者：
Sherman, A
中科院分区：
文献类型：
--
作者：
Pedersen, MG;Bertram, R;Sherman, A
胰腺β细胞的胰岛素分泌是脉动的，周期为5-10分钟，据信是导致血浆胰岛素以相似频率振荡的原因。观察胰岛素原的整体振荡。因此，来自单个β-细胞的胰岛素分泌在胰岛内同步，并且胰岛群也同步是必要的。我们最近开发了一个模型，其中脉动胰岛素分泌产生的结果，钙驱动的电振荡结合糖酵解振荡。我们使用这个模型来研究胰岛内和胰岛间同步的可能机制。我们表明，电耦合是足够的同步电爆发活动和代谢振荡。我们还证明，胰岛可以通过它们对简单模型“肝脏”的影响而相互吸引来同步，肝脏通过以适当的方式调节血糖浓度来响应胰岛素分泌水平。由于所有的胰岛都暴露于血液中，分布式胰岛-肝脏系统可以同步各个胰岛胰岛素振荡。因此，我们证明了如何胰岛内和胰岛间同步胰岛素振荡可以实现。
Insulin secretion from pancreatic beta-cells is pulsatile with a period of 5-10 min and is believed to be responsible for plasma insulin oscillations with similar frequency. To observe an overall oscillatory insulin pro. le it is necessary that the insulin secretion from individual beta-cells is synchronized within islets, and that the population of islets is also synchronized. We have recently developed a model in which pulsatile insulin secretion is produced as a result of calcium-driven electrical oscillations in combination with oscillations in glycolysis. We use this model to investigate possible mechanisms for intra-islet and inter-islet synchronization. We show that electrical coupling is sufficient to synchronize both electrical bursting activity and metabolic oscillations. We also demonstrate that islets can synchronize by mutually entraining each other by their effects on a simple model "liver,'' which responds to the level of insulin secretion by adjusting the blood glucose concentration in an appropriate way. Since all islets are exposed to the blood, the distributed islet-liver system can synchronize the individual islet insulin oscillations. Thus, we demonstrate how intra-islet and inter-islet synchronization of insulin oscillations may be achieved.