Glucose suppresses ATP-inhibited K-channels in pancreatic beta-cells.
Glucose suppresses ATP-inhibited K-channels in pancreatic beta-cells.
复制标题
葡萄糖抑制胰腺 β 细胞中 ATP 抑制的 K 通道。
DOI：
10.1007/978-1-4684-5314-0_5
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发表时间：
1986
影响因子：
--
通讯作者：
Satin,LS
中科院分区：
文献类型：
--
作者：
Cook,DL;Hales,CN;Satin,LS
葡萄糖诱导的胰岛素释放涉及胰腺β细胞中的级联事件：葡萄糖代谢增强细胞对钙的净摄取，从细胞内的钙库中动员钙，从而触发胰岛素的胞吐作用15。当葡萄糖使β细胞膜去极化以触发钙动作电位的周期性爆发时，发生钙摄取2，3，10，13。自20世纪60年代后期以来，葡萄糖代谢与去极化的耦合机制一直困扰着工作者。去极化伴随着细胞输入阻抗的增加，膜电位对外部K+ 2的依赖性降低，以及42 K+和86 Rb +8的流出减少，所有这些都依赖于葡萄糖代谢9，12。这些发现表明存在膜K通道，其在低葡萄糖下开放，并通过与葡萄糖代谢相关的过程关闭。作为可能性，已经提出Ca激活的K通道通过葡萄糖诱导的细胞内游离Ca2+ 2的下降而关闭，或者K通道通过代谢质子产生和细胞内酸化而关闭14。
Glucose-induced insulin release involves a cascade of events in the pancreatic β-cell: the metabolism of glucose enhances the net uptake of calcium by the cell, mobilizes calcium from stores within the cell and thus triggers the exocytosis of insulin15. Calcium uptake occurs when glucose depolarizes the β-cell membrane to trigger periodic bursts of calcium action potentials2,3,10,13. The mechanisms which couple glucose metabolism to the depolarization have eluded workers since the late 1960’s. Depolarization is accompanied by increased cell input impedance, decreased dependence of membrane potential on external K+ 2, and decreased efflux of42K+and86Rb+8, all of which depend on glucose metabolism9,12. These findings have suggested the existence of membrane K-channels which are open in low glucose and are closed by a process linked to glucose metabolism. As possibilities, it has been suggested that Ca-activated K-channels are closed by a glucose-induced fall of intracellular free Ca2+ 2, or that K-channels are closed by metabolic proton production and intracellular acidification14.